PISTON DIS ASSEMBLY & CLEANING

Responsibility: Concerned staff1. DISASSEMBLY

1.1 Place piston and connecting rod assemblies on fixture so that rod hangs down on trolley stand.

1.2 Remove internal snap ring from each side of piston pin with nose plier & remove piston pin.

1.3 Remove piston rings, using ring expander tool1.4 Place connecting rod, caps, bolts and nuts in

cleaning tray & keep in section.2. CLEANING

2.1 PISTONS2.1.1 Put the pistons in cleaning solution of washing

soda & water tank for 8 to 12 hrs. Start the heaters and water-circulating pump. After 12 hrs, stop pump and heater. Let it cool to ambient temp.

2.1.2 Scrap the pistons with the zero emery paper to remove the carbon deposits if any.

2.1.3 Clean with diesel oil and then with water jet in washing shed.

2.1.4 Blow it out with compressed air in the section.

2.2 CONNECTING RODS AND CAPS2.2.1 Clean with diesel oil2.2.2 Blow con rod with compressed air including oil hole.2.2.3 Check if oil rifle hole is clear while blowing with

compressed air.

2.3 PISTON PIN2.3.1 Clean with diesel oil and then blow out with air.

2.4 BIG END BOLTS AND NUTS.2.4.1 Clean in diesel oil and then with dry cloth.2.4.2 Clean with water in washing shed and then blow out

with air.PISTON INSPECTION AND CHECKINGResponsibility: Concerned staff & JE1. PISTON

Record the type of piston, piston No, manufacturing date and name of the manufacturer.Check visually for any damage, pit marks, scratch mark or cracks on it. If found condemn it. Check the ring groove width of piston ring in the following manner

Insert the outside edge of compression ring in groove in four different position and measure side clearance with a feeler gauge

Maintain the following clearance for each groove LimitRing clearance in compression groove 0.008” to 0.012” Ring clearance in 1st groove 0.006”- 0.016” Ring clearance in 2nd groove 0.006”- 0.012” Ring clearance in oil scrapper groove 0.001”- 0.0045”

Limit 0.006”

Check the lifting hole threads and tap the threads.Send the piston to CMT Lab for Zyglo testing.

2.0 PISTON PIN2.1 Visually check for scratch marks, if there is any scratch

mark or rough surface, remove by polishing it with emery paper.

2.2 Do Zyglo test to find out any cracks.2.3 Check tightness of sleeve inside it. If tightness found OK

in visual checking, then test hydraulically at a pressure of 60 PSI. There should not be any leakage of water. In case of leakage, apply the expander to tighten the sleeve, and redo the hyd. test. If still not rectified change the sleeve and check by hydraulic testing again.

3.0 CONNECTING ROD BIG END BOLT & NUT3.1 Send to machine section to enlarge split Pin hole from 3.2

mm to 4 mm on drilling machine, if the hole dia is 3.2mm.

3.2 Visually inspect for any apparent bend, worn out thread, crack etc.

3.3 Zyglo test and record it.3.4 Match bolts and nuts.3.5 Check drill hole with 4 mm split pin.3.6 Check the length of the connecting rod bolt: - 11” +

0.017”.3.7 Check the Hardness of Big End Bolts and only the bolts

having hardness in the range of 28 RC to 32 RC should be used on locos. Record: Format No : DS/PA-0101

Responsibility: Concerned staff & JE

1.0 INSPECTION OF CONNECTING ROD ASSEMBLY

1.1 Match the cap srl Nos. with connecting rod srl nos.1.2 Put the con. Rod with shell bearing on crankshaft crank pin

fixture and assemble the cap with bearing, apply bolts and nuts tighten it evenly in cross wise manner for proper elongation.

1.3 Check the bolt elongation with elongation gauge it should be with in 0.015’ to 0.018”.

1.4 Check the running clearance between crank pin big end bore. It should be 0.004” to 0.008”

1.5Loosen the nuts, remove the bearing cap and shell bearing. Remove con rod.

1.6 Check visually for any wear and tear of little end bush of con. rod. If there is any wear and tear, replace it with new one.

1.7 Check the parallelism between piston pin bore and crank pin bore on parallelism fixture assembled with Cap , in case of any doubt or abnormality observed in 1.2 to 1.4 .

1.8 Do D.P. test for any surface cracks.1.9 If found OK in DP test, place the connecting rod and cap in

a tray and do final cleaning with fresh diesel oil. 2.0 Blow air through that drilled lub oil passage to ensure that it

is fully clean, and the Con Rod is free from any dirt etc.

Record: Format No:DS/PA-0106

Responsibility: Concerned staff & JE

1.0 Place the new piston ring all, one by one before fitment, in the master liner and measure the Ring gap with the feeler gauge. The gap must be within the range, as mentioned below.

Type of Piston Ring Permissible Range

1. Compression 0.050” – 0.085”2. Oil Scrapper Ring 0.020” – 0.045”

ASSEMBLY OF PISTON & CON. RODResponsibility: Concerned staff & JE

1. Check clearance between piston pin and con rod little end bush before assembly. It should be 0.003” to 0.005” and keep it as matching pair.

1.1 Place piston on the assembly fixture.

1.2 Align rod bore with piston pinhole. Apply lube oil coat to all mating surfaces.

1.3 Apply piston pin to piston through Con. Rod little end bush.

1.4 Check clearance between the piston pin to bore. Inserts the piston pin into the piston bore. Check the clearance with feeler gauge.

The clearance should be within 0.0005”-0.0025”. Limit 0.0035”

1.5 Using special nose pliers, press snap ring on both sides of Piston pin.

1.6 Use new piston rings from bottom groove to Top groove by using ring expander.

1.7 Check the clearance between groove and ring by inserting ring out side edge in piston groove at three or four point and measure the clearance with filler gauge between rings & groove on piston.

a)Compression ring, Side gap: 0.006”-0.012”. Limit: 0.016”b)Oil scrapper ring, Side gap 0.001”-0.0045”. Limit : 0.006”

Record: Format No : DS/PA-0102

FITMENT OF EQUIPMENTS1. PISTON

a) Clean all the crank pins properly.b) Connecting rods Big ends & caps are cleaned properly.c) Bearings are fitted on the big ends & caps according to the

marked location & check for tight fitting on big end and caps.d) Piston rings gaps are set at 180º apart.e) Before inserting the pistons lube oil is applied on the inner wall

of the liners properly.f) Bar the Crankshaft to bring the crankpin to BDC Position for

fitting 4 sets of pistons.g) Fit the corresponding big end caps and tight by hand properly.h) Carry out the same process to fit the remaining pistons.

2. ELONGATING BIG END a) Fit the connecting Rod caps with Crank pin journal by Zyglo

tested Big end bolts with castle nuts.b) i) Check fitment of connecting rod caps with the respective

locations, numbers to be outward.ii) All Big end bolts holes for split pin to be drilled to 4mm

dia hole.c) All Big end bolts are to be fitted with Zyglo tested and also all

bolts to be fitted must have been checked for its free length on a special fixture for checking free length.

d)Tighten the bolts to 20 ft-lbs torque diagonally and then finally elongate the bolts to 0.015” elongation. Fit split pin. If hole for split does not coincide further tighten upto 0.018” ,fit the split pin and split the legs fully.

e) Check the side play of the connecting rod big end on the crankpin.

f) Repeat the above process for all the connecting rods.

3. 1R-TDC CHECKINGa) Mount the magnetic base dial indicator on the bloc nearer to 1R-

cylinder liner on which piston fitting and big end elongation is completed.

b) Mark a Dot Punch on the dowel of crank shaft at generator end flange.

c) Bar the crank shaft over until the needle of the dial indicator moves, when 1R piston reaches TDC needle of the indicator will stop & it will move in opposite direction. Stop the barring and set the dial indicator to ‘Zero’-reading.

d) Bar the crankshaft in any direction until the dial indicator needle reaches to 0.050” and stop the barring.

e) Put one pointer of special trammel on Dot Punch on the crankshaft dowel and make an arc with other end of trammel pointer on the face of the block at generator end.

f) Bar the crankshaft in opposite direction until the needle of the dial indicator reaches to zero and comes back to 0.050” again.

g) Make another arc with trammel pointer on the face of the block.h) Draw a straight horizontal line and join both the arcs, this line will

intersect the arcs.i) Bisect the straight line, putting divider on inter section points of arc

& straight line.j) Mark with dot punch at bisecting point.k) Put the trammel on crankshaft dowel and bar the crankshaft in

opposite direction till the trammel pointer coincides with the center point on horizontal line.

l) The dial indicator needle must show “Zero”-reading. This is correct IR- TDC.

m)Set the TDC trammel on the punch mark on crankshaft web and other pointer on the base door of the crank case. If it coincides with previous punch mark on 8L base door then it is OK. If it is not coinciding then punch mark a new one on 8L base door and eliminate the old punch mark on 8L base door.

4. CYLINDER HEADa)Check the straightness of cylinder head studs with a

template from the tools locker.b)Fit the inlet and exhaust push rod grommets. Apply

holdtite between engine bock and grommet and on the upper surface of the grommet.

c)Clean the face of head and liners and piston crowns before loading the cylinder heads.

d)Apply graphite powder on the cylinder head’s stud before fitment of nuts on studs.

e)Mount all the cylinder heads with the help of EOT crane and align with a straight edge.

Tight the nuts with torque wrench at 550 ft-Ib as per tightening sequenceResponsibility: Concerned Staff & JE.

5. AIR INLET ELBOWSa)Clean the air channel in engine block properly.b) Clean the air inlet elbows with HSD oil and water.c)Check and clean the threaded holes in block for fitment

of inlet elbows.d) Apply Flexitallic gaskets and locating plates on top of

inlet elbows to cylinder heads.e)Fit inlet elbow foundation gasket in between engine

block and inlet elbow bottom. Tight by hand properly.f) Secure the top and foundation bolts with clamps

properly.

6. DAMPER EXTENSION SHAFT a) Bar the main engine crankshaft.b) Bring No.1 crankpin to TDC.(Note: 1R Crankpin must be on TDC)c) Clean the damper spider and crankshaft flange properly.d) Ream the threaded hole on the crankshaft flange for mounting the damper

extension shaft properly.e) Mount the vibration damper with the help of EOT crane on the crankshaft

with a suitable eye bolt. f) Mount the extension shaft and hand tight the bolts properly.g) Tight the extension shaft bolts finally with the torque wrench at 450 ft.Ibs. h) After final tightening of the bolts check the run out of damper extension

shaft by using a dial indicator. The limit is 0.006” .i) Finally seal wire the bolts.

.

7. CAM GEAR TIMING j) Bar the main engine crankshaft.k) Bring 1R crank pin to TDC.l) Coincide the punch mark on the crankshaft web and punch mark on the 8L

sump window with a trammel.m)Fit the cam gears on the camshaft.n) Observe cut mark on the top and bottom of cam gear, it should be parallel to

the engine block slant face.o) Apply locktite and tight cam gear nut properly, and seal wire the nut with lock bolt.

Responsibility: Concerned Staff & JE.

8. INSPECTION OF CAM GEAR

a) Clean the cam gears with HSD oil and check physically for any damage or worn out.

b) Remove cam gear nut, key and snap ring.c) Send for DP testing.d) After DP testing reassemble the cam gear and make ready for fitment on

camshaft.e) Drill 4mm hole on the cam gear nut for sealing of locking bolts

properly.

9. TSC SUPPORT

a)Clean the TSC support with HSD oil and water jet.b)Check the threaded holes provided for mounting of after

cooler on it.c)Clean the Engine Block mounting surface of TSC support.d)Check the threaded holes on the TSC support-mounting

surface on the engine block free end as well as on sump.e)Apply gasket of size 1/16” of thickness on the Engine

sump and Block.

10. AFTER COOLER AND TSC

a)Clean the inside of after cooler housing with dry clean cloth.

b)Apply suitable gasket on the after cooler mounting face.c)Mount the after cooler with the help of EOT crane.d)Fasten the mounting bolts and tight it properly.e)Place gasket of size 1/8” thickness on either side of the

support and mount the TSC on it with the help of EOT crane.

f) Fasten the TSC mounting bolts and tight properly.

11. LUBE OIL SECONDARY HEADER

a)Clean lube oil secondary header with HSD oil and water.b)Blow out with dry compressed air.c)Fit the headers on the block on both sides using clamps

and tight properly.

CRANK-SHAFT OVERHAULING AND CHECKINGResponsibility: Concerned staff. & JE

1.0 STRIPPING AND CLEANING

1.1 After splitting cylinder block from base, place the cylinder block in inverted position on pit.

1.2 Uncouple and remove all Main-bearing caps, Remove No 9 upper Main Brg shell (Thrust Bearing).

1.3 Remove cotter pins from all connecting Rod cap bolts. 1.4 Loosen and remove nut from each connecting rod assembly.

1.5 Remove caps from connecting rod assembly.1.6 Continue the process for remaining connecting rod assemblies.1.7 Assemble the lifting tackles to crank shaft to crank pin no. 2 & 7. Lift

crankshaft with crane and place it on cleaning tray. Protect thrust collar, it must not hit E/Block.

1.8 Remove if any upper bearing shells adhering to main journals.1.9 Lift the crankshaft and place it on the flushing stand, keep the main journal

no. 2&8 on “V’ bearing support for flushing crankshaft by diesel oil with a pump.

2 REMOVAL OF THE SPLIT GEAR FROM CRANKSHAFT2.1 Place crankshaft on the surface table, keep on the roller blocks in position

2 & 8.

2.2 Uncouple and remove lifting blocks from crank pins2.3 Cut and remove the locking wire of socket head bolts2.4 Set crank pin no.8 on top position2.5 Loosen and remove socket head bolts.2.6 Hit gently with soft hammer or brass bar on gear assembly to make free

from locating dowels. Hold the lower half and remove it from crankshaft.

2.7 Remove upper half gear by gently hitting on it.

2.8 Apply screw to jacking hole of key and tighten the screw. The key will come out from keyway of crankshaft.

2.9 Remove screw from key.

3.0 CLEANING OF SPLIT GEARClean the gear assembly and socket head bolts with Diesel oil.

Responsibility: Concerned staff., JE & SE

4.0 CHECKINGS OF SPLIT GEAR4.1 Inspect visually any worn out or broken gear teeth.4.2 Check any damage on collar and other portion of gear.

4.3 Conduct DP test for split gear, socket head bolts & key.

5.0 CLEANING5.1 Clean the entire crankshaft with Diesel oil. (Including oil holes)

5.2 Polish the crank journal and main journal after applying diesel with the help of 400/320 silicon papers.

5.3 Blow out the oil holes with compressed air.

6.0 CHECKING OF CRANK PINS OUT OF ROUNDNESS

6.1 Place the crank pin no:2 & 7 on top position. Place the crankshaft on surface table. Do not turn the crankshaft.

6.2 Measure the vertical and horizontal Dia of crank pins with outside micrometer (the measurement should not be less than 5.996”)

6.3 The difference of dia. between vertical and horizontal dia should not exceed 0.002”. If it exceeds, it is out of round then matching to be done by polishing with 400/320-silicon paper.

6.4 Take the measurement keeping crank pin in same position as mentioned above.6.5 Record the above measurement in the Register below.

7.0 MAIN JOURNAL INSPECTION AND MEASUREMENT

7.1 Measure vertical and horizontal dia on either side of oil hole &1” away.

7.2 The minimum dia should not be less than 8.496”, new dia 8.500”7.3 The difference of dia should not be exceed 0.002”.7.4 Record the above measurement in Format No. DS/PP/0103

Record: Format No : DS/PP-0103Responsibility: Concerned staff., JE & SE

8. CHECKING OF CRANK SHAFT RUN OUT8.1 Place crankshaft on No.2 and 8 journals on mounting block on surface table.8.2 Set magnetic base dial indicator on surface table set the dial indicator on flange at ‘0’

reading.8.3 Rotate the crankshaft anti clockwise gently and take readings at 4 points & 90 apart

from each other. 8.4 The maximum run out should not exceed + 0.004”8.5 Total indicated run out should not exceed 0.008”8.6 Start from main journal no. 1.8.7 Repeat the process for remaining journals.

8.7 Take the reading of power take off end of the flange and free end flange in same manner as in case of main journals.

8.8 Check the recess clearance of thrust bearing in No-9 main journal of Engine crank shaft before fitment of Engine block

8.9 Record the measurements in the Register below.9.0 DYE PENETRANT TEST & MAGNAFLUX TEST9.1 Conduct DP Test on all the crank pin & main journal of the crankshaft to detect any

surface crack.9.2 Conduct magna-flux test on all crank pin & journal for any sub surface crack.9.3 If any crack is detected, either surface or sub surface, withdrawal the crankshaft from

service.

10.0FITMENT OF KEYCheck the split gear keyway on the crankshaft. Key should have interference fit of

0.000”-0.005” both in shaft & split gear.

11.0 SPLIT GEAR ASSEMBLY11.1 Assemble split gear on the crankshaft tighten bolt with 300 ft-lb torque

following the snugging up sequence. 11.2 Check the side clearance on the both sides of the split gear, the clearance

should be between 0.007” to 0.023”.11.3 Check the total split gear split line clearance, it should be 0.0015” 11.4 Record the measured clearances in the Format No. DS/PP/010811.5 Seal wire the pairs of bolts.

Record Format No : DS/PP-0104