Turn the crankshaft so that the pistons are below the carbon deposit area, which is located above the area of movement of the piston rings.

Ремонт шатунно-поршневой группы Cummins ISF3.8

Use a fine fibrous abrasive stone and solvent to remove carbon deposits.

Mark the cylinder number on the piston crown.

Remove the connecting rod-piston group.

a) Install the piston to BDC by turning the crankshaft.

Ремонт шатунно-поршневой группы Cummins ISF3.8Ремонт шатунно-поршневой группы Cummins ISF3.8

b) Mark the connecting rod and the cap with the cylinder number.

c) Loosen (but do not remove) the connecting rod bolts.

d) Use a rubber hammer to tap the connecting rod bolts to remove the caps.

e) Remove the connecting rod bolts.

Ремонт шатунно-поршневой группы Cummins ISF3.8

f) Remove the connecting rod cover.

g) Remove the lower connecting rod bearing shell.

Ремонт шатунно-поршневой группы Cummins ISF3.8Ремонт шатунно-поршневой группы Cummins ISF3.8

Make a cylinder number mark and a letter mark on the flat surface of the lower connecting rod bearing shell.

3) Using a hammer handle, push the piston and connecting rod assembly out of the cylinder. Be careful not to damage the connecting rod and the surface of the crankshaft journal.

Ремонт шатунно-поршневой группы Cummins ISF3.8

i) Remove the upper connecting rod bearing shell. Make a mark on the flat surface of the upper connecting rod bearing.

Disassembly

Ремонт шатунно-поршневой группы Cummins ISF3.8Ремонт шатунно-поршневой группы Cummins ISF3.8

Remove the piston rings with an expander.

Remove the retaining rings.

Ремонт шатунно-поршневой группы Cummins ISF3.8

Remove the piston pin (at room temperature) and connecting rod.

Checking ShPG parts

Measure the diameter of the piston skirt 12 mm from the bottom edge of the piston.

Ремонт шатунно-поршневой группы Cummins ISF3.8

Piston diameter:

- nominal 101.864 - 101.887 mm

- rem. (0.5 mm) 102.364 - 102.387 mm

- rem. (1.0 mm) 102.864 - 102.887 mm

Check the clearance between the piston ring and the piston ring groove.

Ремонт шатунно-поршневой группы Cummins ISF3.8

Clearance between groove and piston ring:

- lower compression ring 0.04 - 0.11 mm

- oil scraper ring 0.04 - 0.085 mm

Measure the inner diameter of the piston pin bosses.

Ремонт шатунно-поршневой группы Cummins ISF3.8

- boss inner diameter 42.006 - 42.0012 mm

Measure the diameter of the piston pin

Ремонт шатунно-поршневой группы Cummins ISF3.8

- piston pin diameter 39.99 7 - 40.003 mm

Measure the inner diameter of the connecting rod piston head bushing

Ремонт шатунно-поршневой группы Cummins ISF3.8

- bushing diameter 40.019 - 40.042 mm

If the bushing is out of specification or damaged, replace the connecting rod assembly.

Ремонт шатунно-поршневой группы Cummins ISF3.8

Check the lower end of the connecting rod (with the bushings removed).

a) Lubricate the connecting rod bolts with clean engine oil.

b) Install the cover and bolts with washers on the connecting rod.

c) Tighten the bolts.

d) Use a bore gauge to measure the inside diameter within 20 degrees of each part of the parting line.

e) Measure the inside diameter in a direction perpendicular to the parting line.

Ремонт шатунно-поршневой группы Cummins ISF3.8Ремонт шатунно-поршневой группы Cummins ISF3.8

diameter of the bore for the crankshaft journal in the connecting rod with the bearing removed 72.99 - 73.01 mm If the values differ from the specified, replace the connecting rod.

Check the lower end of the connecting rod (with bushings installed).

Repeat the above check after installing the bearing in the connecting rod.

Diameter of the bore for the crankshaft journal in the connecting rod with the bearing installed:

- nominal 6905 - 69.10 mm;

- rem. (0.25 mm) 68.80-68.85 mm;

- rem. (0.50 mm) 68.55- 68.60 mm.

Check the clearance in the piston ring lock.

Ремонт шатунно-поршневой группы Cummins ISF3.8

a) Push the ring with a piston to a depth (A) of 89 mm from the upper surface of the cylinder block so that the plane of the rings is perpendicular to the cylinder surface.

Ремонт шатунно-поршневой группы Cummins ISF3.8

b) Using a feeler gauge, determine the gap in the piston ring lock.

Gap:

- 1 compression ring 0.29 - 0.58 mm;

- 2 compression ring 0.88 - 1.37 mm;

- oil scraper ring 0.28-0.77 mm.

If the gap in the ring lock does not correspond to the nominal:

- Make sure the ring type matches the catalog number.

- Check the inner diameter of the cylinder.

- Make sure that the measurement of the gap in the ring lock was made at a depth of 50 mm from the top surface of the cylinder block.

- Put on another set of rings.

ShPG assembly

Install the circlip to one side of the piston.

Lubricate the finger and its seats with engine oil.

Install the piston onto the connecting rod.

a) Install the piston on the connecting rod with marks towards the front of the engine.

Note:

- There are three notches on the connecting rod, which should be directed towards the front of the engine.

Ремонт шатунно-поршневой группы Cummins ISF3.8Ремонт шатунно-поршневой группы Cummins ISF3.8

- There is an arrow on the piston crown, which should point towards the front of the engine.

b) Place the piston pin at room temperature (no need to heat the pistons).

c) Install the retaining ring on the opposite side.

Install the piston rings.

a) Using the expander, place the compression rings with the marks facing up.

Ремонт шатунно-поршневой группы Cummins ISF3.8Ремонт шатунно-поршневой группы Cummins ISF3.8

b) Install the oil scraper ring so that the spring expander gap is opposite the scraper lock.

Note: the location of the ring is determined by its profile.

Ремонт шатунно-поршневой группы Cummins ISF3.8

Installation of ShPG

Clean the cylinder block before installing the connecting rod-piston group.

Install the connecting rod bearing shells. Note: The removed connecting rod bearing shells must be installed where they were removed from.

a) Make sure there is no dirt and debris on the connecting rods and the back of the bushings. Do not lubricate the underside of the connecting rod bearings and the lower end of the connecting rod.

b) Install the upper bushing into the connecting rod.

c) The protrusion of the bearing shell must fit into the groove of the connecting rod. The lip of the liner must be flush with the surface under the cover.

If the engine has split-head connecting rods, the lower and upper bearing shells are not interchangeable.

Install the connecting rod-piston group into the cylinder block.

a) Apply assembly lubricant to the bearing surface.

Ремонт шатунно-поршневой группы Cummins ISF3.8Ремонт шатунно-поршневой группы Cummins ISF3.8

b) Lubricate the cylinder wall with clean engine oil.

c) Lubricate the piston rings and piston skirts with clean engine oil.

Ремонт шатунно-поршневой группы Cummins ISF3.8

d) Turn the rings, placing their locks as shown in the figure.

The lock on each ring must not be against the piston pin or other ring locks. An incorrect arrangement of the ring locks will lead to a leakage of the cylinder.

Ремонт шатунно-поршневой группы Cummins ISF3.8Ремонт шатунно-поршневой группы Cummins ISF3.8

e) Compress the piston rings with a special tool.

f) Turn the crankshaft and set the connecting rod journal of the desired cylinder to BDC.

g) Install the connecting rod-piston group into the cylinder with the “Front” mark / arrow towards the front of the engine.

The long section of the lower end of the connecting rod (1) and the recess (2) of the piston skirt must be on the exhaust side. If not, make sure the piston and connecting rod are assembled correctly.

Ремонт шатунно-поршневой группы Cummins ISF3.8Ремонт шатунно-поршневой группы Cummins ISF3.8

We hammer the device with a hammer so that there is no gap between the mating plane of the cylinder block and the lower part of the clamp of the device.

h) Move the piston until the top ring is fully seated in the cylinder. Guiding with your hands from below, install the connecting rod-piston group until it contacts the connecting rod journal

i) Install the bushing in the connecting rod cover.

Ремонт шатунно-поршневой группы Cummins ISF3.8

The protrusion of the liner must fit into the groove in the cover.

Lubricate the liner with Assembly Lubricant (# 23163087). Do not apply grease to the back of the liner!

j) The numbers on the connecting rod and the cover must be the same, the piston must be installed in the appropriate cylinder.

The numbers on the connecting rod and the connecting rod cap should be on the same side of the connecting rod to reduce the likelihood of engine damage while the engine is running.

Install the connecting rod cover and bolts.

k) Tighten the connecting rod bolts.

Torque:

- the first stage - 30 Nm;

- the second stage - 60 Nm;

- third stage - turn 60˚ clockwise

Measure the side clearance between the connecting rod and the crankshaft crank.

Ремонт шатунно-поршневой группы Cummins ISF3.8

- Side clearance 0.125 - 0.275 mm

Measure the protrusion of the piston above the surface of the cylinder block.

Note: This operation is necessary after repair or replacement of the piston, crankshaft, connecting rod or cylinder block.

a) Install the dial indicator on the cylinder block surface and set it to "0".

Ремонт шатунно-поршневой группы Cummins ISF3.8

b) Move the dial gauge directly over the piston pin, avoiding lateral deflection.

Do not touch the indicator protrusion to the galvanized surface.

c) Set the piston to TDC. Determine the maximum protrusion by turning the crankshaft in different directions. Record the measurement results.

Ремонт шатунно-поршневой группы Cummins ISF3.8

Piston protrusion .... 0.151 - 0.485 mm

Ремонт шатунно-поршневой группы Cummins ISF3.8

If the piston protrusion is not correct, check the correct selection of the installed parts and / or the processing of the upper surface of the cylinder block.

Turn the crankshaft and make sure it turns freely.