Danfoss Integrated

IHT-M15

Integrated

Hydrostatic Transaxle

Service Manual

2

IHT-M15 Introduction 1

1. Introduction

1.1 Use of This Manual

This manual includes information for the normaloperation, maintenance, and servicing of the IHT-M15 integrated hydrostatic transaxle. The manualincludes the description of the unit and its individualcomponents, troubleshooting information, adjustmentinstructions, and minor repair procedures. Unit war-ranty obligations should not be affected if mainte-nance, adjustment, and minor repairs are performedaccording to the procedures described in this manual.

The service and adjustment activities described inthis manual can usually be performed without remov-ing the unit from the vehicle. However, adequateaccess to the part of the unit involved must be

1.2 Safety Precautions

Copyright 1996, Sauer-DanfossAll rights reserved. Contents subject to change. Printed in U.S.A.

Loss of Hydrostatic Braking Ability

WARNINGThe loss of hydrostatic drive line power in anymode of operation (e.g. acceleration, decelera-tion or "neutral" mode) may cause a loss ofhydrostatic braking capacity. A braking sys-tem which is independent of the hydrostatictransmission must, therefore, be providedwhich is adequate to stop and hold the systemshould the condition develop.

Disable Work Function

WARNINGCertain service procedures require the vehicle/machine to be disabled (wheels raised off theground, work function disconnected, etc.) whileperforming them in order to prevent injury tothe technician and bystanders.

Fluid Under High Pressure

WARNINGUse caution when dealing with hydraulic fluidunder pressure. Escaping hydraulic fluid un-der pressure can have sufficient force to pen-etrate your skin causing serious injury. Thisfluid may also be hot enough to burn. Seriousinfection or reactions can develop if propermedical treatment is not administered immedi-ately.

Flammable Cleaning Solvents

WARNINGSome cleaning solvents are flammable. Toavoid possible fire, do not use cleaning sol-vents in an area where a source of ignition maybe present.

The procedures herein should be performed by trained personnel only. Observe the following safety precautionswhen using and servicing hydrostatic products.

F100203

available, and the unit must be thoroughly cleanedbefore beginning maintenance, adjustment, or repairactivities. Since dirt and contamination are the great-est enemies of any type of hydraulic equipment,cleanliness requirements must be strictly adhered to.This is especially important when changing the sys-tem filter and during adjustment and repair activities.

A worldwide network of Sauer-Danfoss Autho-rized Service Centers is available should repairs beneeded. Contact any Sauer-Danfoss AuthorizedService Center for details. A list of all Service Centerscan be found in bulletin BLN-2-40527, or in brochureSAW (Ident. No. 698266).

3

IHT-M15 Introduction 1

Table of Contents

1. Introduction ................................................................................................................................................21.1 Use of This Manual ................................................................................................................................... 21.2 Safety Precautions ....................................................................................................................................22. Functional Description ..............................................................................................................................42.1 Component Location ................................................................................................................................. 52.2 Hydraulic Circuit and Components ...........................................................................................................82.3 Mechanical Drive Components ............................................................................................................... 112.4 Control Features .....................................................................................................................................123. Technical Specifications .........................................................................................................................144. Tools and Pressure Measurement .......................................................................................................... 154.1 Required Tools ........................................................................................................................................ 154.2 Pressure Gauge Installation ....................................................................................................................155. Start-up, Fluids, and Filter .......................................................................................................................165.1 Fluids Specification ................................................................................................................................. 165.2 Start-up Procedure ..................................................................................................................................165.3 Fluid and Filter Change ...........................................................................................................................176. Inspections and Adjustments ................................................................................................................. 186.1 Charge Pressure Priority Valve Inspection ............................................................................................. 186.2 Implement Relief Valve Adjustment ........................................................................................................ 196.3 Neutral Return Mechanism Inspection .................................................................................................... 216.4 Pump Neutral Start Switch (NSS) Adjustment ........................................................................................ 236.5 Electrohydraulic Control Inspection ........................................................................................................ 266.6 Speed Sensor Adjustment ...................................................................................................................... 277. Minor Repairs ...........................................................................................................................................287.1 Plug / Fitting Torques ..............................................................................................................................287.2 Shaft Seals ..............................................................................................................................................297.3 Neutral Start Switches ............................................................................................................................ 317.4 Filter ........................................................................................................................................................327.5 Dip Stick, Fill Tube, Breather, and Fill Level Plug ...................................................................................327.6 PTO Auxiliary Mounting Pads ................................................................................................................. 337.7 System Check / High Pressure Relief Valves (SCRs) ............................................................................347.8 Easy-Ride Valves ....................................................................................................................................357.9 Charge Pressure Priority Valve ............................................................................................................... 367.10 Implement Circuit Relief Valve ................................................................................................................377.11 Charge / Implement Pump ...................................................................................................................... 387.12 Neutral Return Mechanism .....................................................................................................................397.13 2-Position Electrohydraulic Control and Bearing Carriers for Variable Motor ......................................... 408. Exploded View Parts Drawings ............................................................................................................... 428.1 Hydraulic Center Section Minor Repair Parts .........................................................................................428.2 Hydraulic Housing Minor Repair Parts and Name Plate ......................................................................... 438.3 Variable Motor Controls Minor Repair Parts ........................................................................................... 448.4 Front Section Minor Repair Parts ...........................................................................................................458.5 Parts Description .....................................................................................................................................46

4

IHT-M15 Functional Description 2

The IHT-M15 integrated transaxle is designed toprovide a complete propel, PTO, and hydraulic pack-age for lower power off-road vehicles. It incorporatesa complete hydrostatic transmission, mechanicalgearbox, drive axle with differential, PTO system withelectromagnetic clutch/brake, and hydraulic pumpwith reservoir and filter in a single unit.

An axial piston design pump and motor are utilized inthe hydrostatic transmission. The variable displace-ment pump incorporates a tiltable trunnion swash-plate allowing direct displacement control. One of twomotor types is used. The fixed displacement motor(MF) has a fixed swashplate. The variable displace-ment motor (MV) option utilizes an electrically oper-ated, 2-position hydraulic control system.

Power is routed from the hydrostatic transmissionthrough either a single speed or a 2-speed mechani-cal gearbox to the differential and drive axles. Anoutput shaft for a mechanical 4-wheel drive steerableaxle may be provided, and a companion steerabledrive axle is available.

The electromagnetic PTO clutch/brake operates inoil to provide long life and smooth operation. A shaftoutput for mechanical PTO drives may be provided,as well as a drive for a PTO hydraulic pump.

A built-in hydraulic gear pump provides charge oilpressure for the hydrostatic transmission through aunique pressure priority valve. Flow from this pump isavailable for auxiliary hydraulic services via an imple-ment circuit. The pump utilizes the transaxle housingas a reservoir. A suction-type filter is provided on thetransaxle housing.

2. Functional Description

IHT-M15WITH FIXED MOTOR IHT-M15

WITH VARIABLE MOTOR

Rear Right

Left Front

IHT-M15 with Different Motor Options - Orientation Used in This Manual

Note: Actual orientation will vary with application. This orientation applies to applications with the unit in thefront axle position.

E100032

5


Front Cover

Axle

ElectrohydraulicControl

Gear Housing

Hydraulic Housing

Hydraulic Center Section

Axle

2.1 Component Location

The IHT-M15 is made up of several major assemblysections. The hydraulic center section contains mostof the porting and pressure control mechanisms. Thehydraulic housing contains the pump and the motor.The gear housing contains the gearing between theinput and output shafts. The front cover closes thehousing and mounts the auxiliary pads.

The assemblies are shown for reference only. Ser-vice activities do not involve the disassembly of themajor sections.

CAUTIONDisassembly of the major sections is not aservice activity. Any disassembly of the majorsections will void the unit warranty. Incorrectassembly of the interior components can se-verely damage the unit.

The following two pages display outline drawingsshowing the location of the IHT-M15 componentscovered in this service manual.

Major Assembly Sections

E100049

6


IHT-M15 Outlines Showing Features (Fixed Motor Unit Shown) (A)

Implement Circuit Relief Valve

Range Control Neutral Start Switch

Pump Control Shaft

Range Control Shaft

Implement Pump

Integral Filter

TOP VIEW

Input Shaft

4WD Shaft

Charge Pressure Valve

System Check / High Pressure Relief Valves

Easy-Ride Valves

Variable Motor Control(not shown)

REAR VIEW

Fill Tube

PTO Clutch Connector

Dip Stick

Speed Sensor(not shown)

Implement ReturnAuxiliary Pad(no pad shown)

Oil Drain

Fill Level Plug

FRONT VIEW

Breather Vent

P100111P100112P100113

7


ImplementCircuit Port

Charge PressurePriority Valve

Pump NeutralStart Switch

Neutral Return Mechanism

LEFT SIDE VIEW

System Check / High Pressure Relief Valves

IHT-M15 Outlines Showing Features (Fixed Motor Unit Shown) (B)

Control Port(for Variable Motor)

Pump Control Shaft

PTO Shaft

Range Control Neutral Start Switch

Range Control Shaft

Auxiliary Pad(no pad shown)

RIGHT SIDE VIEW

System Check / High Pressure Relief Valve

Speed SensorPort

P100114P100115

8


Basic Closed Circuit

The main ports of the pump are connected internallyin the hydraulic center section to the main ports of themotor. Fluid flows, in either direction, from the pumpto the motor then back to the pump in this closedcircuit. Either of the hydraulic passages can be underhigh pressure. The position of the pump swashplatedetermines which passage is high pressure as wellas the direction and amount of fluid flow.

2.2 Hydraulic Circuit and Components

Input PVMV

(MF)

Case

Output

Flow (Bidirectional)

Reservoir

PV MF(MV)

Inlet Filter


Charge / Implement

Pump

25cc Fixed or Variable

Motor

Charge Pressure

Priority Valve

15cc Variable

Pump

Reservoir

Open Center Valve(s) for Steering / Implement Circuit(s)

(Customer Supplied)

Recommended Return Filter(Customer Supplied)

Heat Exchanger(Customer Supplied)

PF

IHTÐM15 Hydraulic andHydrostatic Components

(Included in IHTÐM15)

Complete Hydraulic Circuit Schematic for IHT-M15

P100116

P100117

Basic Hydraulic Closed Circuit Schematic

9


Inlet Filter


Charge / Implement

Pump

Charge Pressure

Priority Valve

Reservoir

Ope

n C

ente

r V

alve

(s)

For

S

teer

ing

/ Im

plem

ent C

ircui

t(s)

(Cus

tom

er S

uppl

ied)

Recommended Return Filter

(Customer Supplied)

Heat Exchanger(Customer Supplied)

PF

SystemCheck Valves

System CircuitHigh Pressure

System CircuitLow Pressure

Charge / Implement Hydraulic Pump

A fixed displacement (gear type) pump is installed onthe hydraulic housing and is driven off the closedcircuit pump shaft. The pump supplies cool fluid to thesystem, keeps the system charged, supplies fluid tooperate the motor control system, and provides flowto the auxiliary hydraulic circuits. Charge pressure isregulated by a pressure priority valve.

FilterThe pump draws fluid from the transaxle housing. Anintegral inlet filter is provided to insure that only cleanfluid enters the system.

Heat Exchanger

A heat exchanger, with a bypass valve, is required tocool the return flow from auxiliary hydraulic circuitfluid before it returns to the transaxle housing.

Charge Pressure Priority Valve

Charge pressure is controlled by a priority pressurevalve which directs flow from the charge /implementhydraulic pump. Priority flow from this valve is di-rected to the charge circuit. Once the desired chargepressure is reached, excess flow is directed to theimplement circuit.

When pressure in the implement circuit increases,this valve acts as a pressure reducing valve to main-tain the charge pressure at a constant level.


A relief valve is provided to protect the implementcircuit from overload. The setting of this valve isadjustable and set at the factory.

Poppet

Spring

O-Ring

Plug

Seal Lock Nut

Adjusting Screw

PlugO-Ring

Spring Charge Pressure Priority Valve Spool

Charge / Implement Circuit Schematic

Cross-Section of Implement Relief Valvein IHT-M15 Housing

Cross-Section of Charge Pressure Priority Valvein IHT-M15 Housing

P100118

P100119

P100120

10


System Relief Valves (SCRs)

Combination system check / high pressure reliefvalves are provided in the hydraulic center section forclosed loop overload protection. These cartridge typerelief valves are factory set, and are not field adjust-able. Changing the maximum system pressure canbe accomplished by installing different cartridgeswith the desired setting.

Easy-Ride Valves

The Easy-Ride valves work to reduce the rate ofchange in acceleration (ÒjerkinessÓ) of the vehicle bylimiting the rate of pressure rise in the closed loop.These valves permit flow from the high to the lowpressure side of the loop (through the charge circuit)when loop pressure increases suddenly.

Each Easy-Ride valve consists of a poppet-piston,sleeve assembly, spring, and plug, which are in-stalled in the hydraulic center section. The poppet-piston and its seat form a valve to close off thepassage between one side of the closed loop and thecharge pressure passage. The spring pre-loads thesleeve assembly and holds the poppet-piston closedagainst its seat in the end cap when loop pressure islow.

"Easy-Ride"Valves

System Check / High Pressure Relief

Valves

Charge Pressure

System Loop, High or Low Side

System Loop, High or Low Side

Plug

O-Ring

Cone Spring


From Closed Loop(System Pressure)

To Charge Checks(Charge Pressure)Poppet-Piston

Sleeve Assembly

Spring

Plug

Cross-Section of Easy-Ride Valve in IHT-M15 Housing

Cross-Section of System Relief Valvesin IHT-M15 Housing

Schematic of System Relief and Easy-Ride Valves

P100121

P100123

P100122

11


2.3 Mechanical Drive Components

PTO System

Drive Axle

Mechanical Reduction Drive

Mechanical Reduction DriveHelical gears are used for quiet operation. The pinionfor the mechanical drive reduction is splined to thehydrostatic motor shaft when the gear changer cou-pling is engaged via a shift yoke. The gear changercan be shifted to a neutral position-disengaging thefinal drive. A two speed option is available.

Differential and Drive Axle

Spiral bevel gears are used for final vehicle drivereduction. A forging is used for a single piece axledesign with double row tapered roller bearings.

PTO System

Helical gears are used for quiet operation to drive thePTO system. An electromagnetic clutch/brake whenenergized engages the PTO system. In the non-energized state springs load the brake discs to stopthe PTO system.

PTO Auxiliary Pads

Auxiliary pads allow the PTO to be mounted with anauxiliary gear pump. Different pads allow for differentmating standards.

Drive Shaft

Electromagnetic Clutch/Brake

PTO Auxiliary Pad Option

Mechanical PTO Shaft

Input Shaft

Hydrostatic Pump and Motor

4WD Output Shaft

Axle Shaft

Disc Brake (Option)

Disc Brake (Option)

Axle Shaft

Low RangeHigh Range (Option)

Electromagnetic PTO Clutch / Brake

Auxiliary Flange Shaft

PTO Output Shaft

Mechanical Schematic for IHT-M15

Motor Shaft

Spiral BevelDrive Shaft

Low RangeHigh Range

Range Control Collar

4WD Shaft

Pump Motor

P100124

P100125

P100126

P100127

12


Variable Motor 2-Position ElectrohydraulicControl

This control utilizes an electric solenoid operated 2-position hydraulic valve to port charge pressure toeither of the motor displacement control pistons. Themotor is normally held at its maximum displacement.Energizing the solenoid will cause the motor to go toits minimum displacement.

Pump Neutral Return Mechanism

The pump neutral return mechanism maintains andreturns the pump swashplate to neutral position. Themechanism requires that the displacement controllinkage contain less than 2 Nm (20 in•lbf) of friction.

If the neutral return mechanism is off-center, it can beadjusted as in Sec. 6.3.

Control Piston

Variable MotorControl Housing

Motor Trunnion

Control Arm

Solenoid

Pump Swashplate Trunnion

Neutral Return Assembly

2.4 Control Features

Pump Neutral Return Mechanism

Cross-Section of Variable Motor andElectrohydraulic Control

in IHT-M15 Housing

P100129

P100128

13


Neutral Start Switches (NSS)

The IHT-M15 may have neutral start switches toensure engine engagement does not occur with theunit out of neutral.

The pump neutral start switch provides a means toprevent the vehicle engine from starting while thepump swashplate is in a position which would placethe pump "in-stroke" in either the "forward" or "re-verse" direction.

When the pump swashplate trunnion is in its "neutral"position (zero displacement), the inner end of theswitch pin moves into a slot on an eccentric camwhich is linked to the swashplate via a lever. Thisallows the spring-loaded NSS to close, completingthe electrical starting circuit for the vehicle engine.

When the swashplate shaft is NOT in its "neutral"position, the eccentric cam moves the switch pin outof the slot. This forces the NSS to open, breaking theelectrical starting circuit for the vehicle engine.

The range control neutral start switch works in asimilar manner. It permits the engine to start onlywhen the range control is set at neutral. This preventsthe drive function from being suddenly engaged atstart-up.

Speed SensorAn optional speed sensor can be installed to providemotor speed information. The sensor reads a mag-netic ring on the motor cylinder. Pin NSS

Location of Neutral Start Switchesand Speed Sensor Port

Cross Section of Pump Neutral Start Switchin Neutral Return Mechanism(Range Control NSS Similar)

Pump NeutralStart Switch

LEFT SIDE VIEWRange Control

Neutral Start Switch

RIGHT SIDE VIEW

Speed SensorPort

P100130

P100131

14

IHT-M15 Technical Specifications 3

3. Technical Specifications

Maximum Input Power

26 kW (35 horsepower)

Maximum Weight on the Axle

Up to 1600 kg (3520 lb)Will vary by application.

Input Speed

Designed for 2600 to 3600 rpm rated engines

Output SpeedsSingle or two-speed final ratios are available withfixed or variable motor inputs.

Pump Displacement

15 cm3/rev

Motor Displacement

25 cm3/rev fixed or maximum variable13 cm3/rev minimum variable

Charge Pump Displacement

6.4 cm3/rev (0.39 in3/rev)

Maximum Axle Output Torque

2170 Nm (1600 ft•lbf)

Rated Axle Output Torque875 Nm (650 ft•lbf)Will vary by application.

Caliper Disc Brake Capacity (Option)

Contact Sauer-Sundstrand for options and speci-fications.

PTO and Auxiliary Pad Speeds

Up to 2000 rpm.Exact speed will vary depending on engine speedand available ratios.

PTO Torque

Maximum: 107 Nm (945 in•lbf)Continuous: 85 Nm (756 in•lbf)Continuous torque capacity will vary by applica-tion.

Electromagnetic PTO Clutch BrakePerformance

Brake torque (static): 30 Nm (22 ft•lbf)Three second stop time from 2000 rpm: 2.8 Nm2

(6.8 lbf•ft2) free inertia

Hydraulic Implement CircuitImplement flow: 11 l/min (3 gpm) at 50 bar (725 psi)Implement relief valve setting: 70 bar (1000 psi)standard - may be other setting tailored to applica-tion (see Sec. 6.2).

Reservoir Capacity

Integral reservoir in housing holds approximately11 liters (3 U.S. gallons), depending upon axlewidth

Unit Weight117 kg (258 lb)

15

IHT-M15 Tools and Pressure Measurement 4

4. Tools and Pressure Measurement

4.1 Required Tools

The service procedures described in this manual forthe IHT-M15 transaxle can be performed using com-mon mechanic's tools.

4.2 Pressure Gauge Installation

Pressure gauges should be calibrated frequently toensure accuracy. Snubbers are recommended toprotect pressure gauges.

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Pressure gauges are used to measure pressure atvarious points in the hydraulic circuit. The IHT-M15has dedicated gauge ports for system pressure andcharge pressure. Implement circuit pressure can bemeasured by teeing into the implement circuit hosethat exits the implement outlet port. Case pressure ismaintained at atmospheric pressure through thebreather vent.

NOTE: Implement circuit pressure can be mea-sured directly from the implement circuit outletport. However, as this forces flow through theimplement circuit relief valve, heat will generatequickly. The IHT-M15 should not be run for morethan a short period in this way.

WARNINGFluid under high pressure. Do not remove orinstall gauges or plugs when the engine is on.

Charge Pressure Gauge Port "M3"

System Pressure Gauge Ports "M1" and "M2"

TOP VIEW

Auxiliary Charge Pressure Gauge Port M6 (Fixed Motor Only)

RIGHT SIDE VIEW

ImplementCircuit Port

LEFT SIDE VIEW

For proper hose torques, see Sec. 7.1.

Location of Gauge Ports

P100132

P100133

16

IHT-M15 Start-Up, Fluids, and Filter 5

This start-up procedure should always be followedwhen starting-up a new IHT-M15 installation.

WARNINGThe following procedure requires the vehicleto be disabled (wheels raised off the ground orother precautions taken) while performing theprocedure in order to prevent injury to thetechnician and bystanders. Take necessarysafety precautions before moving the vehicle/machine.

Make certain all system components (reservoir, hoses,valves, fittings, heat exchanger, etc.) are clean priorto filling with fluid.

Fill the housing reservoir with recommended fluidwhich should be passed through a 10 micron (nomi-nal, no bypass) filter prior to entering the reservoir.The use of contaminated fluid will cause damage tothe components.

When the housing reservoir is filled to the proper levelthe filter will be full of fluid. Check that the inlet filtercartridge is properly tightened to avoid leakage.

Install a 50 bar (500 psi) pressure gauge in the chargepressure gauge port to monitor charge pressureduring start-up.

Place the range control in its neutral position. It isrecommended that the external control input linkagebe disconnected at the pump control until after initialstart-up. This will allow the pump to remain in its"neutral" (zero-flow) position.

"Jog" or slowly rotate the vehicle engine until chargepressure starts to rise. Start the vehicle engine and

run at the lowest possible RPM until charge pressurehas been established.

WARNINGDo not start vehicle engine unless pump is in"neutral" position (0° swashplate angle) andthe range control mechanism is in neutral.Take precautions to prevent vehicle move-ment in case pump is actuated during initialstart up.

Once charge pressure has been established, in-crease speed to normal operating RPM. Chargepressure should be 5.5 bar (80 psi) minimum and amaximum of 9 bar (130 psi). If charge pressure isincorrect, shut down and determine cause for im-proper pressure.

Shut down vehicle engine and connect external con-trol linkage to the pump. Start vehicle engine, check-ing to be certain pump remains in neutral. Engage themechanical gearbox and, with vehicle engine at nor-mal operating speed, slowly check for forward andreverse vehicle operation.

Charge pressure should remain at 5.5 bar (80 psi)minimum during forward or reverse operation. Con-tinue to cycle slowly between forward and reverse forat least five (5) minutes.

Shut down vehicle engine, remove gauges, and plugports. Check fluid level and add fluid if necessary.Avoid overfilling unit. Overfilling unit will result inadditional horsepower loss and heat generation.

The transaxle is now ready for operation.

Acceptable fluids must have additives that provideacceptable performance when operating with multi-disk brake and clutch components.

Most premium tractor fluids are suitable for operationin the IHT-M15. Mobil 424 or its equivalent is recom-mended by the factory.

Automatic transmission fluids such as Type F and

5. Start-up, Fluids, and Filter

5.1 Fluids Specification

Dextron should not be used. Use of these fluids willresult in a reduction of component life.

Rapeseed-based oils are not recommended for use.Premium synthetic ester oils, such as Mobil Syndraulic46 should provide service life similar to mineral basedoils under similar conditions. Change interval mustbe decreased to 75% of recommendations in section5.2.

5.2 Start-up Procedure

17

IHT-M15 Start-Up, Fluids, and Filter 5

To ensure optimum service life of the IHT-M15transaxle, regular maintenance of the fluid and filtermust be performed.

Check the housing daily for proper fluid level. Thefluid level should fall between the "Add" and "Full"lines on the dipstick. Also check for the presence ofwater (noted by a cloudy to milky appearance of thefluid), and rancid fluid odor (indicating excessiveheat).

It is recommended that the fluid and filter be changedper the vehicle/machine manufacturerÕs recommenda-tions or initially after 200 hours and then at 600 hourintervals of vehicle operation.

CAUTIONAvoid overfilling or underfilling the unit. Over-filling unit will result in additional horsepowerloss and heat generation. Underfilling the unitwill in serious damage.

It may be necessary to change the fluid more fre-quently than the above interval if the fluid becomescontaminated with foreign matter (dirt, water, grease,etc.) or if the fluid has been subjected to temperaturelevels greater than the maximum recommended.Never reuse fluid.

After filling, run the unit and its implement circuitbriefly and recheck the fluid level.

NOTE: When on a level surface, the proper oillevel is to the base of the fill level plug on the backof the IHT-M15.

The filter should be changed whenever the fluid ischanged. See section 7.11 for instructions on chang-ing the filter.

The transaxle is supplied with a filter installed at thefactory. A factory supplied filter replacement is rec-ommended. A suction filter with time waited averageratings of β

10 = 5.5 and β

20 = 75 is required.

Oil Drain

Fill Level Plug

5.3 Fluid and Filter Change

Fill Tube

Dip Stick

Filter

Location of Fluid and Filter Components

P100135P100136

18

IHT-M15 Inspections and Adjustments 6

6. Inspections and Adjustments

6.1 Charge Pressure Priority Valve Inspection

Incorrect charge pressure can lead to improper func-tioning of many systems. A charge pressure that istoo low or too high may be the result of the chargepressure priority valve sticking. This can be remediedby removing and cleaning the valve per Sec. 7.8.

Check charge pressure as follows.

WARNINGThe following procedure requires the vehicleto be disabled (wheels raised off the ground,etc.) in order to prevent injury to the technicianand bystanders.

1. Disable vehicle by raising wheels off of ground.

2. To measure charge pressure, install a 35 bar (or500 psi) pressure gauge in the charge pressuregauge port.

3. Operate the system with the pump in "neutral"(zero angle) and in forward and reverse whenmeasuring charge pressure.

Charge pressure should be between 5.5 and 9 bar(80 to 130 psi) at 1800 engine rpm and a fluidtemperature of 49°C (120°F ).

If charge pressure is too low or high, follow Sec. 7.8to remove and clean the charge pressure priorityvalve. Ensure the valve and spring are reinstalledproperly.

Charge PressureGauge Port

Charge Pressure Gauge Port

Location of Charge Pressure Priority Valve

E100033

P100155

Charge PressurePriority Valve

19


Implement circuit pressure can be measured, and theimplement relief valve can be adjusted. However, therelief valve is set at the factory, and should not betampered with except to remedy an inadvertent ad-justment.

WARNINGThe following procedures require the vehicleto be disabled (wheels raised off the ground,etc.) in order to prevent injury to the technicianand bystanders.

Measuring Implement Circuit Pressure1. With engine off, set a pressure gauge to measure

implement circuit pressure by teeing into theimplement hose that is connected to the imple-ment circuit outlet port.

2. Measure standard implement pressure with en-gine input speed at 1800 rev/min and the pump inneutral.

The correct setting for implement circuit pressure willvary depending on your application and gear ratios.The "nominal" relief setting is set for 2 l/min (0.5 gpm)flow moving through the valve. However, in checkingcircuit pressure, it is easiest to measure pressure at"full" relief flow (11 l/min (3 gpm)); this pressure willmeasure 8 bar (120 psi) above the nominal setting.As an example, for a nominal relief setting of "70 bar"("1000 psi"), implement circuit pressure should read78 ± 1 bar (1120 ± 15 psi) at full relief flow.

To adjust implement circuit pressure continue below.

(continued)

6.2 Implement Relief Valve Adjustment

Exploded View of Implement Relief Valveon IHT-M15

Location of Implement Relief Valveand Implement Circuit Port

78 bar(1120 psi)

70 bar(1000 psi)

2 l/min(0.5 gpm)

11 l/min(3 gpm)

"nominal" setting

"full" setting

graph to show trend only -- not exact

Trend Graph Showing Relation of ÒNominalÓ andÒFullÓ Implement Relief Valve Settings

E100034

P100157

G100001

ImplementRelief ValveImplement Circuit

Outlet Port

20


Spring

Poppet

Adjusting Screw

O-Ring

Plug

Seal Lock Nut

Implement Relief Valve Components(Do Not Remove When Engine Is On!)

Adjusting Implement Relief Valve Setting

WARNINGThe implement relief circuit is under high pres-sure. Do not remove the implement relief seallock nut and/or the adjusting screw.

1. Loosen the seal lock nut with an 7/8 in hexwrench. Do not remove.

2. The adjustable screw (4 mm int. hex) sets thepressure setting. Do not remove. With the pumpin neutral, adjust the screw and retighten the seallock nut. Observe the implement circuit pressuregauge. Only a slight adjustment should be neces-sary.

WARNINGThe implement relief valve should only be setat the setting specified for the model. Too highof a setting can damage the unit or auxiliaryequipment, and harm the operator or bystand-ers. Too low of a setting could weaken theimplement function.

3. After the proper setting is made, stop the engine.Retorque the seal lock nut [33 Nm (24 ft•lbf)].Remove the pressure gauge. The implementcircuit hose should be torqued to [41 Nm (30ft•lbf)].

E100035

21


The pump swashplate neutral return mechanism isinstalled and adjusted at the factory to provide neu-tral. If the unit fails to return to its "neutral" position, itcould be due to the external control linkage. If the unitfails to return to neutral with the external controllinkage disconnected, then follow the steps below tocenter the neutral return mechanism.

WARNINGThe following procedure requires the vehicleto be disabled (wheels raised off the ground,service and parking brakes applied, etc.) inorder to prevent injury to the technician andbystanders.

1. Disable the vehicle by raising wheels, applyingparking brake, etc.

2. Disconnect the external control linkage from thepump swashplate shaft.

3. Remove the four (4) screws retaining the neutralreturn mechanism cover with a 10 mm hex wrench.Remove the cover and gasket as required.

4. Check the linkage and spring for looseness andwear. The spring tie bolt must not be loose on thespring and the spring must not be loose in itscylinder. The lever must be firmly clamped to theswashplate shaft. No looseness is allowed any-where in the linkage.

If looseness or wear is observed, the neutralreturn mechanism must be replaced (Sec. 7.12).

5. Loosen (4) screws (item 191) but do not remove.Screws should be snug but allow neutral returnplate to move.

(continued)

6.3 Neutral Return Mechanism Inspection

Neutral ReturnPlate

Screw

Screw (4x)

Lock Nut

Neutral Return Handle


Linkage

Spring

Relative Locations of Neutral Return Mechanismand Pump Swashplate Linkage

Neutral ReturnMechanism

Compartment

Location of Neutral Return Mechanism

Neutral Return Mechanism (Cover Removed)

Pump SwashplateTrunnion

Neutral ReturnMechanism

Compartment

P100139

P100140

P100141

22


Neutral Return Plate Torque Sequence

6. Remove two system pressure gauge port plugsand install a differential pressure gauge. Thegauge will be used to measure system pressurefor setting neutral.

7. With prime mover running, rotate square trunnioncontrol handle until zero differential pressure ismeasured on the pressure gauge (maximum of50 psi differential pressure allowed). The neutralreturn plate should move with a slight drag. If not,tighten the screws slightly. Hand tighten in theorder shown and verify differential pressure isbelow 50 psi.

8. Torque screws to 11 Nm (8 ft•lbf) using the sametorque sequence. Verify that neutral is still presentby rotating the control handle and checking thedifferential pressure.

9. Install a new cover plate gasket. Install coverplate and snug screws. If unit is equipped withneutral start switch in neutral return cover followthe procedure in Sec. 6.4 to properly center andset switch. Torque the cover plate screws to 11Nm (8 ft•lbf).

10. Remove gauge(s) and reinstall plugs into systempressure gauge ports. Torque plugs to 68 Nm (50ft•lbf).

1

32

4

System PressureGauge Ports

Location of System Gauge Ports

Neutral Return Plate Position Should AdjustIn This Direction

P100143

P100142

E100036

23


6.4 Pump Neutral Start Switch (NSS) Adjustment

The Pump NSS must be adjusted to meet the follow-ing requirements:

i. The angle through which the swashplate shaftcan be turned without opening the NSS is calledthe "NSS deadband." The angle through whichthe swashplate shaft can be turned without mov-ing the swashplate enough to build 7 bar (100 psi)differential system pressure in either direction iscalled the "swashplate shaft deadband." Thesedeadbands must be centered in relation to eachother.

Since the position of the swashplate shaftdeadband cannot be adjusted, the position of theNSS deadband must be adjusted to match it. Theswitch is located in a special adjusting plug in theneutral return mechanism cover. The position ofthe cover may be changed to move the center ofthe NSS deadband.

ii) The NSS deadband must be narrow enough sothe NSS will open before the unit builds 7 bar(100 psi) differential system pressure in eitherdirection.

The neutral start switch is threaded into thespecial adjusting plug. Turning the special plugclockwise (CW) into the cover will move the NSScloser to the switch cam on the neutral returnlever, and will narrow the NSS deadband. Turn-ing the special plug counterclockwise (CCW) outof the cover will move the NSS farther from theswitch cam on the neutral return lever, and willwiden the NSS deadband.

WARNINGThe following procedures require the vehicleto be disabled (wheels raised off ground, etc.)to prevent injury to the technician and by-standers.

(continued)

Neutral Start Switch

Pin

Adjusting Plug

NSS Cam

NotchLock Nut

Switch Cam

Location of Pump Neutral Start Switch

Neutral Start Switch CamWithin Neutral Return Mechanism

Cross Section of Pump Neutral Start Switch

Pump NSS

P100144

P100145

P100146

24


Centering the Pump Neutral Start Switch(Condition i)

The NSS deadband and the swashplate shaftdeadband must be centered in relation to each other.

The neutral return mechanism adjustment should bechecked and adjusted to locate the swashplate in its"neutral" position prior to adjusting the position of thecover (Sec. 6.3).

1. Hold the special plug from turning with a 1 inchhex wrench and use a 7/8 inch hex wrench toremove the neutral start switch.

2. Loosen the four (4) cover screws with a 10 mmhex wrench.

3. Locate the switch pin in the slot of the switch camby moving the cover while checking the pin posi-tion (depth) in the plug. When the pin engages thecam slot, the pin will be at its maximum depth inthe plug. Hand tighten the cover screws to holdthe special plug in position.

4. Turn the swashplate shaft an equal amount ineither direction from "neutral." The switch pinshould move out of the special plug an equaldistance when the swashplate shaft is turned.Move the cover to center the switch pin with thecam slot. Only a small amount of adjustment ineither direction should be needed to center thepin.

5. While holding the cover in place, tighten the coverscrews to 11 Nm (8 ft•lbf). Reinstall and adjust theswitch as outlined in the previous section.

6. Recheck switch continuity to determine whetheradditional adjustment of the cover or special plugis necessary.

7. After verifying proper control and switch opera-tion, stop the vehicle engine. Remove the conti-nuity checker and pressure gauges. Reinstall thepressure gauge port plugs and reconnect theelectrical leads from the vehicle starter circuit tothe neutral start switch. Reconnect and adjust, ifnecessary, the swashplate control linkage.

(continued)

Cover Screws

NSS Must Be Centered on Cam

Adjust Cover to Center NSS on Cam

P100147

P100148

25


Neutral Start Switch Deadband Adjustment(Condition ii)

The width of the NSS deadband can be adjusted byaltering the distance of the NSS pin from the cam.

1. Disconnect the external control linkage and makecertain the swashplate shaft is in its "neutral"position.

2. Using a 1 inch and a 1-1/8 inch hex wrench, holdthe special plug from turning and loosen thelocknut.

3. Attach a continuity checker to the terminals of theswitch. With the swashplate shaft in its "neutral"position, turn the special plug clockwise (CW)until electrical continuity is broken, then turn theplug counterclockwise (CCW) until electrical con-tinuity is obtained. Turn the plug counterclock-wise (CCW) an additional 1/8 turn after continuityhas been obtained.

4. Hold the plug in place and tighten the locknut to33 Nm (24 ft•lbf) torque.

5. With the continuity checker attached to the switch,rotate the swashplate shaft in each direction toassure continuity is broken when the shaft is notin the "neutral" position.

6. If continuity is obtained in "neutral" and satisfac-torily interrupted in each direction, proceed tocheck the switch with the vehicle engine running.The switch must open between 4 and 7 bar (60and 100 psi) differential loop pressure in eitherdirection.

7. If the switch opens after the unit builds looppressure in either direction, loosen the lock nutand turn the plug clockwise (CW) 1/12 of a turn.Tighten the lock nut and recheck the switchoperation. Repeat this procedure if necessary.

8. If neutral start switch operation is satisfactory,reconnect the external swashplate shaft linkage.

If continuity is not interrupted with an equalmovement of the swashplate shaft in each direc-tion, perform the "Centering Pump Neutral StartSwitch" procedure preceding this section.

Adjusting Plug

Lock Nut

Adjustment of NSS Deadband

P100149

26


6.5 Electrohydraulic Control Inspection

The variable motor is normally held at its maximumdisplacement. Energizing the solenoids shifts themotor to minimum displacement.

If the motor fails to shift, check to ensure that chargepressure is at the correct setting (Sec. 6.1). Alsocheck the solenoid continuity.

If the solenoid is operating correctly and chargepressure is correct, cleaning the supply line orifices inthe servo piston housing may be required (Sec. 7.13).

Solenoid

Electrohydraulic Control on IHT-M15P100150

27


Positioning Speed Sensor Relative to Motor Shaft

Cross Section of Speed Sensor Set in Port

When installing or adjusting the speed sensor on theIHT-M15, it must be set at a specific distance from thespeed ring on the motor cylinder. To locate theposition of the speed sensor on the unit, see theoutline drawings in Sec. 2.

1. Loosen the sensor lock nut with an 11/16 inch hexwrench.

2. Turn the sensor clockwise (CW) by hand until itcontacts the speed ring.

3. Turn the sensor counterclockwise (CCW) 1/2turn (180°) to establish the nominal gap of 0.71mm (0.028 in).

4. Then turn the sensor clockwise (CW) until thewrench flats on sensor body are positioned at a22° angle to the motor shaft center line.

NOTE: The motor shaft is parallel to the inputshaft. Many adjustable wrenches have a 22°handle offset.

5. The final sensor position should be between 1/2(180°) and 1/4 turn (90°) counterclockwise (CCW)from the point where the sensor contacts thespeed ring.

6. Hold sensor in position with a 1/2 inch hex wrenchwhile tightening the lock nut to 13 Nm (10 ft•lbf).

6.6 Speed Sensor Adjustment

P100159

P100158

1/2 in. Wrench Flats

22ϒ

1/2 in. Wrench Flats

22ϒ

Shaft Centerline

Shaft Centerline

OR

Magnetic Speed Ring

Speed Sensor

GapMotor Cylinder

Lock Nut

28

IHT-M15 Minor Repair Instructions 7

7. Minor Repairs

is adequate, providing clean solvent is used. As withany precision equipment, the internal mechanismand related items must be kept free of foreign mate-rials and chemicals.

Protect all exposed sealing surfaces and open cavi-ties from damage and foreign material.

It is recommended that all gaskets and O-rings bereplaced. All gasket sealing surfaces must be cleanedprior to installing new gasket. Lightly lubricate all O-rings with clean petroleum jelly prior to assembly.

Minor Repairs may be performed, following the proce-dures in this section, without voiding the unit war-ranty.

Keep in mind that the case of the IHT-M15 is a fluidreservoir. Many minor repairs will require the fluid tobe drained. Remember to refill the fluid and start theunit according to procedures described in Sec. 5.

Cleanliness is a primary means of insuring satisfac-tory transaxle life, on either new or repaired units.Cleaning parts by using a solvent wash and air drying

If any plugs or fittings are removed from the transaxleduring servicing, they should be torqued as indicatedin the accompanying table.

Always install new O-rings before reinstalling theplugs or fittings.

7.1 Plug / Fitting Torques

Description Torque

3/8-24 O-ring 11 Nm 1/2 inch Hex Wrench (8 ft•lbf)






7/8-14 O-ring 68 Nm 1 inch Hex Wrench (50 ft•lbf)

29


Pump Control Shaft Seal

Flat Washer

Retaining Ring

Range Control Shaft Seal

Retaining RingBearing

2WD

4WD

Retaining Ring

Input Shaft Seal

Plug

Retaining Ring

Bearing

4WD Shaft

4WD Shaft Seal

Retaining Ring

Retaining Ring

Less Mechanical PTO

With Mechanical PTO

Retaining Ring

Plug

PTO Shaft Seal

Exploded View of IHT-M15 Shaft Seals(Fixed Motor IHT-M15 Shown)

Rubber coated lip type shaft seals are used in theIHT-M15 transaxle. These seals can be replacedwithout major disassembly of the unit. Seals or sealplugs are used around the input shaft, the 4WD shaft,the PTO shaft, the range control shaft, and the pumpcontrol shaft. All are similarly secured with a retainingring except for the pump control shaft seal which isretained with a C-ring and a washer.

If leakage from a seal is noted, it should be replaced.When replacing a seal, examine the seal contactsurfaces for nicks or scratchiness. Ideally, a conedassembly sleeve (a "bullet") and a press-fitting toolare used in pressing a new seal.

(continued)

7.2 Shaft Seals

E100037

30


Replacing Shaft Seals

1. Disconnect the shaft from its mate or linkage.

2. Remove the seal retaining ring with snap ringpliers. For the pump control shaft seal remove theflat washer as well.

3. Carefully remove the seal from its bore. The faceof the seal may be punctured with a sharp instru-ment (such as a screw driver) to aid in prying theseal out, or a slide hammer type puller may beused to remove the seal. Care must be taken soas not to damage the bore, shaft, or bearing.Once removed, the seal is not reusable.

4. Inspect the new seal, the shaft bearing, and theseal bore for damage. Inspect the sealing area onthe shaft for rust, wear, or contamination. Polishthe sealing area on the shaft if necessary.

5. Place a coned assembly sleeve ("bullet") over thesplined end of the shaft to prevent damage to theseal lip during installation. Lubricate the insidediameter of the new seal with petroleum jelly.

6. Using an appropriate press-fitting tool, press thenew seal into its bore. Be careful not to damageseal.

7. Install the retaining ring. (For the pump controlshaft, the flat washer goes inside of the retainingring.) Reconnect the engine drive shaft / 4WDdrive shaft / PTO shaft / range control linkage/pump control linkage.

NOTE: Transaxles without 4WD or PTO shaftswill have plugs installed in the shaft bores. Theseplugs may be removed and installed in the samemanner as the shaft seal.

Coned Assembly Sleeve

Press-Fitting Tool

Seal

A "Bullet" Protects the Seal from InstallationDamage

The Press-Fitting Tool should Contact Seal nearSeal O.D.

P100151

P100152

31


Pump NSS

The neutral start switch is removed and installed asfollows. For proper operation, the NSS must beadjusted per Sec. 6.4 before final installation.

1. Remove NSS [7/8 in hex] and its O-ring.

2. Remove lock nut [1 in hex].

3. Remove adjuster plug [1-1/8 in hex], its O-ring,and contact pin.

4. Install fresh O-ring and contact pin on NSS plug.Install adjuster plug into NSS cavity [33 Nm (24ft•lbf)]. This should be set per Sec. 6.4.

CAUTIONThe NSS must be properly adjusted accordingto Sec. 6.4 for correct operation.

5. Install lock nut.

6. Install NSS [33 Nm (24 ft•lbf)].

7. Check continuity.

Range Control NSSThe NSS for the range control can be removed toinstall a new O-ring or switch.

1. Remove NSS [7/8 in hex] and contact pin.

2. Install fresh O-ring on NSS.

3. Install new contact pin in cavity.

4. Install NSS [33 Nm (24 ft•lbf)].

5. Check continuity.

Pump NSS

Range Control NSS

7.3 Neutral Start Switches

Pump NSS on Neutral Return Mechanism Cover

Range Control NSS on Right Side of IHT-M15

Cover

Plug Assembly(Less NSS)

O-Ring

Lock Nut

Pin

Adjuster Plug

Neutral Start Switch (Pump)

O-Ring

O-Ring

Gasket

Screw

Pin

Neutral Start Switch(Range Control)

O-Ring

Exploded View of Pump NSS Components

Exploded View of Range Control NSS Components

P100153

P100154

E100038

E100039

32


The dip stick and fill tube, the breather vent, and thefill level plug can be removed to replace an O-ring orthe entire assembly. If leakage has been occurring,inspect the mating surfaces for nicks or roughness.

NOTE: Correct oil level is to the base of the filllevel plug.

Breather Assembly

O-Ring

O-Ring

Fill Level Plug

Screw (4x)10 mm Hex

Filler Tube

O-Ring

Dip Stick1 in Hex

68 Nm (50 ft•lbf)

14 Nm (10 ft•lbf)

3/4 in Hex

11 Nm (8 ft•lbf)

7.5 Dip Stick, Fill Tube, Breather, and Fill Level Plug

Exploded View Showing Dip Stick, Fill Tube, Breather, and Fill Level Plug

E100040

The integral filter should be replaced as often asspecified in Sec. 5.3.

The filter nipple does not need to be removed. Ifremoved, it is installed into the hydraulic centersection, and is torqued to 41 Nm (30 ft•lbf).

A factory supplied filter replacement is recommended.When a Sauer-Danfoss filter is not available use asuction filter that has a time weighted averagerating of β

10 greater than 5.5 and β

20 greater than 75.

FilterCannister

Nipple

7.4 Filter

Exploded View of Filter on IHT-M15

E100053

33


Auxiliary mounting pads can be installed to accom-modate an auxiliary gear pump. The auxiliary mount-ing pad may also be removed to change the coupling.

1. Remove the cover screws, the cover, and its O-ring.

2. Remove the auxiliary pad screws, the auxiliarypad, its O-ring, and the coupling.

NOTE: Different auxiliary pads use differentcouplings.

3. Install coupling over PTO shaft.

4. Install O-rings on auxiliary pad and cover.

5. Install the auxiliary pad or "no pad"[54 Nm (40 ft•lbf)].

6. Install the cover, if no pump is mounted[SAE A ⇒ 61 Nm (45 ft•lbf),SAE B ⇒ 98 Nm (73 ft•lbf)].

Exploded View of IHT-M15 PTO Auxiliary Mounting Pads

No Auxiliary Pad

SAE "A" Auxiliary Pad

SAE "B" Auxiliary Pad

"No Pad"

Screw (4x) (17 mm hex)

Screw (2x) (9/16 in hex)

Seal Ring

Pad

Coupling

Washer

Screw (4x)(8 mm int. hex)

Screw (2x)(17 mm hex)

CoverO-Ring

Screw (4x)(17 mm hex)

WasherPadO-Ring

Coupling

O-Ring

O-Ring

Cover

7.6 PTO Auxiliary Mounting Pads

E100041

34


The system check and relief valves (SCRs) can beremoved to inspect the valves and the seats, and toreplace O-rings or the assembly. It will be necessaryto replace the center section if the seats are dam-aged.

1. Remove the check and high pressure relief valveplugs with a 7/8 inch hex wrench.

2. Remove the cone spring from the plug or from thevalve. Remove the valve from the hydraulic cen-ter section.

3. Inspect the valves and mating seats in the centersection for damage or foreign material.

4. Install new O-rings on the special plugs.

5. Reinstall the valves into the center section. Installthe check valve springs onto the valves with thelarger diameter OUT (toward the plug).

6. Install the plugs and torque to 41 Nm (30 ft•lbf).

CAUTIONThe relief valves are factory set and should notbe tampered with except for replacing the en-tire valve.

Plug

O-Ring

Cone Spring


Plug

Check / Relief Valve

Conical Spring

O-ring

7.7 System Check / High Pressure Relief Valves (SCRs)

Exploded View of System Check / High PressureRelief Valves on IHT-M15

System Check / High Pressure Relief ValveComponents

Cross Section View of System Check / HighPressure Relief Valves in IHT-M15

E100042

E100043

P100122

35


The easy-ride valves can be removed to inspect thevalves and the seats, and to replace O-rings or theassembly.

1. Remove the easy-ride valves by removing thehex plugs using an 11/16 inch hex wrench.

2. Remove the spring and sleeve assembly with thepoppet/piston.

3. Remove the poppet/piston from the sleeve as-sembly.

4. Inspect the seat area in the hydraulic centersection for damage or foreign material. Inspectthe seat and orifice of the poppet/piston for dam-age or foreign material. The poppet/piston mustslide freely in the sleeve assembly. Inspect thespring for damage.

5. Reinstall the poppet/piston into the sleeve as-sembly. Install the sleeve assembly, spring, andplug with a new O-ring. Torque the plug to 41 Nm(30 ft•lbf). Spring

Sleeve Assembly

Poppet-Piston

Plug

O-Ring

Poppet-Piston

Sleeve Assembly

Spring

O-Ring

Plug

7.8 Easy-Ride Valves

Exploded View of Easy-Ride Valves on IHT-M15

Easy-Ride Valve Components

Cross Section View of Easy-Ride Valves in IHT-M15

E100045

E100044

P100156

36


The charge pressure priority valve can be removed toinspect the valve and to replace O-rings or the as-sembly. Any foreign material can affect the operationof the valve.

1. Remove the charge pressure priority valve plugwith a 11/16 inch hex wrench.

2. Remove the spring and spool.

3. Inspect the spool and its bore for damage orforeign material.

4. Install the spool and spring. Check spool orienta-tion (spring end outward).

5. Install the plug and torque to 41 Nm (30 ft•lbf).

6. Check the charge pressure (Sec. 6.1).

PlugO-Ring

Spring Charge Pressure Priority Valve Spool

Plug Assembly

Spool

Spring

O-Ring

7.9 Charge Pressure Priority Valve

Exploded View of Charge Pressure Priority Valve onIHT-M15

Charge Pressure Priority Valve Components

Cross Section of Charge Pressure Priority Valvein IHT-M15 Housing

E100046

E100047

P100119

37


The implement circuit relief valve should be removedonly if leakage is noted or the valve is not functioningproperly.

1. Remove the implement relief valve plug with a 7/8 inch hex wrench.

2. Remove the spring and poppet.

3. Remove the seal lock nut with a 17 mm hexwrench. Remove the adjusting screw with a 4 mminternal hex wrench.

4. Inspect the poppet and mating seat for damageor foreign material.

5. Install the adjusting screw into the special plugand install the seal lock nut.

6. Install the poppet and spring. Install the plug andtorque to 68 Nm (50 ft•lbf).

7. Check the implement circuit pressure (see Sec.6.2).

8. After the implement circuit pressure is set, torquethe seal lock nut to 33 Nm (24 ft•lbf).

Spring

Poppet

Adjusting Screw

O-Ring

Plug

Seal Lock Nut

Poppet

Spring

O-Ring

Plug

Seal Lock Nut

Adjusting Screw

7.10 Implement Circuit Relief Valve

Exploded View of Implement Circuit Relief Valve onIHT-M15

Implement Circuit Relief Valve Components

Cross Section of Implement Circuit Relief Valvein IHT-M15 Housing

P100120

E100035

E100034

38


The charge / implement gear pump can be removedto replace the seals. If damage to the gear splines isnoted, the gear pump should be replaced.

1. Remove the four (4) screws holding the gearpump to the hydraulic center section with a 9/16hex wrench and remove the pump. Remove thegear pump parts. Note orientation of each part.

NOTE: The gear pump parts are loose when thescrews are removed. Take care not to drop andlose parts.

The inside spacer does not fall out of the IHT-M15housing. It contains a bearing that is pressed intothe IHT-M15 housing. The spacer needs to berotated back and forth to ease it out of thehousing.

2. Remove the drive coupling from the pump driveshaft.

3. Examine the coupling and the shaft splines. Ex-amine the gear splines.

4. Assemble the end cap, outside seals, outsidespacer, gears, gear housing, inside spacer, andinside seals together. Use fresh seals. Orienta-tion must be as per the original assembly, thisincludes the outside spacer and the idle gear.

NOTE: The inside seals will have a tendency tocome out of place when assembled to the IHT-M15 housing. Care must be taken to ensure theyare assembled in place. Petroleum jelly shouldhold the seals in place.

5. Insert washers and screws through assembly. Anold O-ring (or similar) can be wrapped around theends of the screws to hold the assembly togetherduring installation.

6. Install the gear pump assembly to the IHT-M15housing with the screws and washers [47 Nm (35ft•lbf)].

Seal Kit

Flat WasherScrew

Charge / Implement Pump

Drive Coupling

End Cap

Outside SpacerDrive Gear

HousingInside Spacer

Inside Seals

Outside Seals!

!Idle Gear

! Orientation, although not obvious, is important.

7.11 Charge / Implement Pump

Exploded View of Charge / Implement Gear Pump onIHT-M15

Charge / Implement Gear Pump Components

Bearing

Inside Spacer with Raised Bearing

E100050

E100051

E100052

39


The neutral return mechanism can be removed toinspect and replace. There should be no looseness inthe mechanism.

1. Thoroughly clean external surfaces prior to re-moval of the neutral return mechanism cover.

2. Using a 10 mm hex wrench, remove the four (4)cover screws. Remove the cover assembly andgasket from the hydraulic unit housing.

CAUTIONProtect exposed surfaces and cavities fromdamage and foreign material.

3. Using a 10 mm hex wrenches, remove the nutand screw retaining the lever to the pump controlshaft.

4. Using a 10 mm hex wrench, remove the four (4)mounting plate screws. Remove the mountingplate from the hydraulic unit housing.

5. Inspect all parts for looseness or wear. Theneutral return spring must not be loose in itscanister.

WARNINGIf the neutral return spring shows looseness orwear, replace entire neutral return mechanism.

6. The external and internal pump control shaftsmust not exhibit any relative movement whentwisted.

7. Install the mounting plate and screws. Tightenthe screws hand-tight.

8. Install the lever onto the internal pump controlshaft and torque the nut to 14 Nm (10 ft•lbf).

9. Adjust the neutral return mechanism (Sec. 6.3),and torque the mounting plate screws to 11 Nm(8 ft•lbf).

10. Install a new gasket on the housing. Place thecover plate into position, align the gasket andinstall the screws. Torque the screws to 11 Nm (8ft•lbf).

11. Check and adjust the neutral start switch on thecover, if installed (see Sec. 7.13 for installationand Sec. 6.4 for adjustment).

Neutral ReturnPlate

Screw

Screw (4x)

Lock Nut

Neutral Return Handle


Linkage

Spring


Compartment

Pump Swashplate

Trunnion

7.12 Neutral Return Mechanism

ScrewNut

LeverScrew

Mounting Plate

ShoulderScrew

Screw

Cover Assembly

Cover Gasket

CoverScrew

Centering Spring Assembly

Relative Location of Pump Trunnionand Neutral Return Mechanism


Neutral Return Mechanism Components

E100054

P100141

E100055

40


Disassembly of Control

1. Thoroughly clean external surfaces prior to re-moval of the control.

2. Disconnect the external electrical signal connec-tion.

3. The solenoid coil may be removed from the valveby removing the nut with a 3/4 inch hex wrench.The solenoid valve may be removed from thecontrol housing with a 7/8 inch hex wrench.

4. Remove the O-rings and back-up washers fromthe control valve.

5. Remove the pressure supply hose with a 9/16inch hex wrench. Loosen the lock nuts on theelbow fittings with a 9/16 inch wrench and removethe fittings from the hydraulic center section andthe control housing.

6. Remove the six (6) screws retaining the controlcover to the control housing using a 10 mm and5/8 in hex wrench.

7. Loosen the control lever with a 5 mm internal hexwrench and a 10 mm hex wrench. Pull out thecontrol lever.

8. Remove the four control housing screws with a 5mm int. hex wrench. Pull off the control housingand remove the locating pin. Remove O-ring.

9. Remove the control piston covers with a 10 mmhex wrench. Remove control piston gasket.

10. Inspect the orifice plug.

11. Pull the bearing carrier out of the housing.

12. Inspect all parts for damage.

(continued)

7.13 2-Position Electrohydraulic Control and Bearing Carriers forVariable Motor

Solenoid

Control Cover Retaining Screws

Control HousingRetaining Screws

Control Piston

MotorTrunnion

Control Piston

Lever

Control Piston Cover Retaining Screws

SolenoidRetaining Nut

SupplyHose

Elbow

Orifice Plug (2x)

O-Ring

Bearing Carrier

Screw

O-Ring

O-Ring

O-Ring

Bearing Carrier

Hose

Elbow Fitting

Elbow Fitting

Pin

2-Position Electrohydraulic Control on IHT-M15

Partial Cross Section of 2-Position ElectrohydraulicControl

2-Position Electrohydraulic Control Components (A)

E100056

P100160

E100057

41


ScrewCover

Control Piston

Gasket

Control HousingScrew

LeverNut

GasketCover

Screw

Screw

Orifice Plug

O-RingPlug Assembly

ScrewRoller

Pin

Retaining Ring

Control PistonGasketCover

Screw

Orifice Plug

Solenoid Valve

Seals

CoilNut

Installation of Control

1. Replace orifice plugs, if removed [6 Nm (4 ft•lbf)].

2. Install new control piston gasket on control hous-ing. Install control piston cover screws [15 Nm (11ft•lbf)].

3. Install the bearing carrier so the swashplate en-ters the bearing. Install a new O-ring onto thehousing, and retain with petroleum jelly. Installthe locating pins.

4. Install the control housing over the swashplatecontrol shaft and onto the housing. Install newinternal hex head screws [11 Nm (8 ft•lbf)].

5. Install control lever over trunnion. Tighten screwand nut [11 Nm (8 ft•lbf)].

6. Install control cover with screws. The smallerscrews are torqued to 15 Nm (11 ft•lbf), the largerscrews to 33 Nm (24 ft•lbf).

7. Install the elbow fittings into the hydraulic centersection and the control housing. Install the pres-sure supply hose and torque to 11 Nm (8 ft•lbf).Do not allow the hose to twist. Torque the locknuts on the elbow fittings to 11 Nm (8 ft•lbf).

8. Install new O-rings and back-up washers onto thecontrol valve.

9. Install the solenoid valve into the control housing,and torque the valve to 41 Nm (30 ft•lbf). Installthe solenoid onto the valve, and torque the nut to7 Nm (5 ft•lbf). DO NOT OVER-TORQUE THENUT.

10. Reconnect the external electrical signal connec-tion.

Left Side Variable Motor Bearing Carrier1. The bearing carrier opposite the control shaft

may be removed after removing the hex screwswith a 10 mm hex wrench. Pull the carrier out ofthe housing.

2. Inspect the journal bearing for damage or wear.

3. Install a new O-ring onto the carrier. Install thecarrier so the swashplate enters the bearing.Install new hex screws and torque to 11 Nm (8ft•lbf).

2-Position Electrohydraulic Control Components (B)

Exploded View of Left Bearing Carrier Assembly

O-Ring

Bearing Carrier

Screw

E100058

E100059

42

IHT-M15 Exploded View Parts Drawings 8

8. Exploded View Parts Drawings

8.1 Hydraulic Center Section Minor Repair Parts

79C

79B79A

79

140

140

17

171

86171

56

154

17171

56

2WD

4WD

70

101102

25

54

53

109

96

94

106

105

139

97

109

133

WITH E-H CONTROL ONLY 220

94

198

CW ROTATION ONLY

9697

110

232(CW ROT. ONLY)

D

C

B

F

E

E100060

43


8.2 Hydraulic Housing Minor Repair Parts and Name Plate

224

222

225

223

19139

43

30

31

46

193

81

194

195

76

19747

5150

48

4266

167

165

191

196

J

ModelNumber

SerialNumber

Place of Manufacture

Name Plate (U.S.A. Production)

Ames, Iowa, USA NeumŸnster, Germany

Model No. Indent-Nr

Serial No. Fabr-NrMADE IN USA

Model code Typ

E100061

P100134

3159001

A-95-46-56789

44


118

75

214

204

212205

216

211203

206

215

214

118

221219

210

212205204

214

220

220(REF)

218

133 (REF)

G

H

K

L

217

8.3 Variable Motor Controls Minor Repair Parts

E100062

45


8.4 Front Section Minor Repair Parts

119

158171

LESS MECHANICAL PTO

LESS AUXILIARY PAD

SAE "A" AUXILIARY PAD

SAE "B" AUXILIARY PAD

WITH MECHANICAL PTO119

115

28171

130

128

161

160162

168

148

163166

147

145

143

142141

169

131149

131

131

E100063

46


8.5 Parts Description

Item numbers correspond with those in the preceding exploded views.

B Implement relief valve assembly 1C SCR valve kit, 415bar/6020 psi 1D Charge pressure priority valve kit 1E SCR valve kit, 415bar/6020 psi 1F Easy ride valve kit 2G Trunnion bearing carrier assembly 1H Trunnion bearing carrier assembly 1J Neutral return assembly 1K Control housing assembly 1L Control arm assembly 1

17 Plug 125 Gear pump coupling 128 Lip seal 130 Screw 131 Shoulder screw 139 Lock nut 142 Lip seal 143 Screw 146 Neutral return cover 147 Neutral return gasket 148 Retaining ring 150 Washer 151 Seal 153 Filter union 154 Filter 156 Ball bearing 366 Retaining ring 170 Lip seal 171 Bore plug 175 Screw 476 Neutral switch 179 Gear pump 179A Screw 479B Lock washer 479C Seal kit 181 Plug 186 Lip seal 194 SCR valve 296 Plug 297 O-ring 2

Qty. PerItem Description Model


101 Plug 2102 O-ring 2105 Relief valve plug 1106 O-ring 1109 Plug 3110 Plug 1115 Breather vent 1118 O-ring 2119 Plug 3128 Screw 4130 Gerotor cover 1131 O-ring 1133 Plug 1139 Seal nut 1140 Plug 2141 Washer 4142 Screw 4143 O-ring 1145 "B" pad cover 1147 Screw 2148 Coupling 1149 Coupling 1158 Bore plug 1160 "A" pad cover 1161 Screw 2162 O-ring 1163 Washer 2165 Neutral switch 1166 Screw 2167 Neutral switch needle roller 1168 "A" pad 1169 "B" pad 1171 Retaining ring 5191 Screw 8193 Drive screw 2194 Nut 1195 Adjuster 1196 Pin 1197 O-ring 1198 Plug 1203 Control housing gasket 1

47



204 Servo cover 2205 Servo cover gasket 2206 Control cover 1210 Screw 1211 Lock nut 1212 Control piston 2214 Screw 14215 Screw 4216 Screw 4217 Solenoid valve 1218 Pin 2219 Plug 1220 Elbow 2221 Hose assembly 1222 Dipstick housing 1223 Dipstick 1224 Screw 4225 O-ring 1232 Plug 1

Overhaul seal kit 1

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Genuine PartsOriginal

Ersatzteile

SM-IHT E • 08/96 • 300098ABLN-10098 • Rev. A • August 1996

SAUER-DANFOSS COMPANY2800 East 13th StreetAmes IA 50010 • U.S.A.Phone: (515) 239-6000 • FAX: (515) 239-6618

SAUER-DANFOSSPostfach 2460 • D-24531 NeumünsterKrokamp 35 • D-24539 Neumünster • GermanyPhone: (04321) 871-0 • Fax: (04321) 871 465

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