Steering Systems Chapter 44. Steering system problem diagnosis Steering system maintenance Steering...
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Transcript of Steering Systems Chapter 44. Steering system problem diagnosis Steering system maintenance Steering...
Steering Systems
Chapter 44
Steering system problem diagnosis Steering system maintenance Steering column service Manual steering gearbox service
(recirculating-ball type) Steering linkage service Manual rack-and-pinion service Power steering system service
Symptoms of steering problems include play in the steering wheel, hard steering, and abnormal noises when turning
Inspect and test the steering system to find the source of the trouble
Steering System Problems
Steering Wheel Play
Amount that you can turn the steering wheel without front wheel movement
Caused by worn ball sockets, a worn idler arm, or too much clearance in the steering gearbox
Compare the play to service manual specifications e.g. 1 1/2” (33 mm)
Dry Park Test
With the vehicle on the ground, rotate the steering wheel back and forth while
someone watches for part wear
Steering Inspection
Raise the vehicle on a lift. Wiggle thetires back and forth while watching
for steering play
Hard Steering Caused by problems with the steering
gear, power steering components, ball sockets, and the suspension system
Check the power steering pump belt for condition and tension
If the belt is slipping, hard steering could result
Check for cracks and glazing and compare tension to specs
Steering System Noise Noise can be a sign of worn parts, dry
bearings or ball sockets, loose parts, slipping belts, or low power steering fluid level
Belt squeal and power steering pump noise both occur when the steering wheel is turned
Pump noise can result from low fluid level or aerated fluid
Maintenance involves checking for low fluid level, incorrect belt adjustment, system leaks, and other problems
Ball socket lubrication may be necessary
Checking the Fluid
Check most systems at operating temperature, with the engine off
Servicing the Belt
When changing a belt, pry on a
recommended point and adjusttension to specs
Service is needed after a collision or when internal parts of the column fail
Most repairs can be done without column removal
Steering Column
Steering Wheel Removal
Remove the horn button and steering shaft nut
Scribe alignment marks on the steering wheel and the steering shaft
Mount a wheel puller over the steering wheel
Screw the bolts into the threaded holes in the steering wheel
Steering Wheel Removal
Tighten the puller down against the steering shaft to remove the wheel
Steering Wheel Installation
When installing the steering wheel, match any alignment marks
Many steering shafts use a master spline so that the wheel only installs in one position
Ignition lock, turn signal mechanism, and horn and cruise control slip rings are all accessible below the steering wheel
Service involves the adjustment or the replacement of worn parts (bearings, seals, and bushings)
Gearbox repair or overhaul may be necessary when adjustment will not provide proper operation
Gearbox Adjustment Two basic adjustments are performed on
manual recirculating-ball gearboxes: Worm bearing preload
preloads the bearings to ensure that the worm shaft is held snugly in the housing
Over-center clearance controls the amount of lash between the
pitman shaft gear and the teeth on the ball nut
Gearbox Adjustment
Worm Bearing Preload Adjustment
Disconnect the pitman arm Loosen the pitman shaft over-center locknut
and adjusting screw Using a torque wrench or spring scale, turn
the steering wheel slowly from side-to-side
Worm Bearing Preload Adjustment
Compare the required force to
specs
If needed, tighten or loosen the
adjustment nut
Over-Center Clearance Adjustment
Center the steering gear in its travel Preload is produced in the center of travel to
avoid steering wheel play during straight-ahead driving
Over-Center Clearance Adjustment
Loosen the locknut and bottom the adjustment screw lightly
Over-Center Clearance Adjustment
Use a torque wrench or spring scale to measure the amount of force needed to move the shaft back and forth through center
Tighten or loosen the adjusting screw until the amount of force needed to move the shaft is within specs
Tighten the locknut after adjustment and recheck the required force
Over-Center Clearance Adjustment
When your inspection finds worn steering linkage parts, new parts must be installed
Steering System Inspection
Idler Arm Service Idler arm wear will cause play in the
steering wheel To check an idler arm, force it up and
down using a spring scale When the specified force is applied to the
spring scale each way, note the idler arm movement and compare to specs e.g. at 20 lbs (9.0 kg) of force, maximum 1/4”
(6.5 mm) travel
Idler Arm Service To replace the idler arm, remove the cotter
pin and castle nut Use a fork tool or puller to force the ball
stud out of the hole in the center link Unbolt the idler arm from the frame Install the new part Torque the idler arm to specifications Install a new cotter pin
Tie-Rod End Service
Tie-rod end wear will cause steering play To remove a tie-rod end, separate the tie-rod
end from the steering knuckle or center link
Tie-Rod End Service
Use a fork or puller to separate the tie-rod end from the steering knuckle
Tie-Rod End Service
Loosen the adjusting sleeve, and count the number of turns required to remove the tie-
rod from the sleeve
Tie-Rod End Service Install the new part the exact same
number of turns Install the tie-rod ball stud into the center
link or steering knuckle Tighten all of the fasteners to specs and
install a new cotter pin Check toe adjustment with an alignment
machine
Service involves the adjustment or the replacement of worn bearings, seals, and bushings
Hoses, a pump, a power piston, and a control valve are added these parts can require repair or replacement
Power Steering Leaks
To check for leaks, wipe fluid-soaked areas clean
Have a helper idle the engine and turn the steering wheel to the right and left
Watch for leaks as the wheels are turned, raising system pressure
Leakage Points(Rack-and-Pinion)
Leakage Points(Linkage System)
Servicing Hoses Always check hose condition when
servicing a power steering system High-pressure hoses are exposed to
tremendous pressures over 1000 psi (6895 kPa)
When installing a new hose, start fittings by hand
Use a tubing wrench to tighten the hose fittings properly
Pump Replacement
Bolts, hoses, and brackets that must be
removed when replacing a pump
Pump Service
During a pump rebuild, clean and inspect all the parts
Check the pump vanes, thrust plate, and pump ring (included in a pump rebuild kit)
Replace all o-rings, gaskets, and seals Lubricate the components with fluid and
reassemble the pump
Bleeding the System
When hydraulic components are serviced, bleed any air out of the system
Idle the engine and turn the steering wheel fully from side to side
Check the fluid level often Cycling the system will force air from the
steering gear, back to the reservoir
Electronic Assist Steering Service
Refer to service manual diagrams, part locations, and electrical value charts
Use a scan tool to check for diagnostic trouble codes
Check scan data for input and output data that could help isolate a problem
Perform pinpoint tests with a multimeter to verify the source of any problems