Connecting Rod: Service and Repair

Piston, Connecting Rod, and Bearing Replacement

Tools Required
* J 24086-B Piston Pin Remover/Installer Set
* J 45059 Angle Meter
* J 8037 Ring Compressor or equivalent
* J 8087 Cylinder Bore Gage or equivalent
* KM-470-B Angular Torque Gage

Removal Procedure





Caution: Refer to Safety Glasses Caution Safety Glasses Caution.

1. Remove the cylinder head with the intake manifold and the exhaust manifold attached. Refer to Cylinder Head Replacement Service and Repair.
2. Remove the oil pan. Refer to Oil Pan Replacement Service and Repair.
3. Remove the oil pump/pickup tube bolts.
4. Remove the oil pump/pickup tube.
5. Remove the engine block lower support and the splash shield bolts.
6. Remove the engine block lower support and the splash shield.




7. Move the piston to the bottom of the piston stroke.
8. Mark the connecting rod cap for position.
9. Remove the connecting rod cap bolts.
10. Remove the connecting rod cap and the lower connecting rod bearing.
11. Remove the upper piston connecting rod bearing.
12. Ridge ream the cylinder wall.





Caution: Handle the piston carefully. Worn piston rings are sharp and may cause bodily injury.

13. Remove the piston.
14. Use a piston ring expander tool to expand the piston rings.
15. Remove the piston rings.




16. Remove the piston pin from the piston and connecting rod assembly using the J 24086-B (1).
17. Separate the piston from the connecting rod.

Inspection Procedure





Caution: Refer to Safety Glasses Caution Safety Glasses Caution.

1. Inspect the connecting rod for bending or twisting. If the connecting rod is bent or twisted, replace the connecting rod.
2. Inspect the connecting rod bearings.
3. Inspect the connecting rod lower end for wear.
4. Inspect the connecting rod upper end for scoring.
5. Inspect the crankshaft rod bearing journal for wear. Refer to Engine Mechanical Specifications Service Limits & General Specifications.
6. Inspect the piston for scoring, cracks, and wear.
7. Inspect the piston for taper using a micrometer.




8. Inspect the piston for fit to the connecting rod.




9. Inspect the engine block deck surface for flatness using a straight edge and a feeler gage. Refer to Engine Mechanical Specifications Service Limits & General Specifications.
10. Inspect the bearing bore for concentricity and alignment using the J 8087 (1). Refer to Engine Mechanical Specifications Service Limits & General Specifications.
11. If the bearing bore is beyond specifications, replace the engine block.
12. Inspect the engine block cylinder bore for wear, runout, ridging and taper using the J 8087 . Refer to Engine Mechanical Specifications Service Limits & General Specifications.
13. Inspect the engine block cylinder bore for glazing.
14. Lightly hone the cylinder bore as necessary.

Installation Procedure





Important: For ease of installation of the piston pin, the connecting rod should be heated to 280°C (536°F). Heat the upper connecting rod only. Use commercial thermocolor material to determine the correct temperature. When the thermocolor material changes from black to green, the temperature is correct for installation.


1. Align the notch on the piston and the connecting rod so that the proper sides will be facing the front of the engine.
2. Install the piston pin guide through the piston and the connecting rod.
3. Coat the piston pin with clean oil.
4. Install the piston pin into the opposite side of the piston.
5. Install the piston pin into the piston and the connecting rod assembly using the J 24086-B (1).




6. Select the set of new piston rings.
7. Measure the piston ring gap using a feeler gage. Refer to Engine Mechanical Specifications Service Limits & General Specifications.
8. Increase the piston ring gap by carefully filing off excess material if the piston ring gap is below specifications.




9. Measure the piston ring side clearance using a feeler gage. Refer to Engine Mechanical Specifications Service Limits & General Specifications.
10. If the piston ring is too thick, try another piston ring.
11. If no piston ring can be found that fits to specifications, the piston ring may be ground to size with emery paper placed on a sheet of glass.




12. Install a piston oil ring, the expander, then the second piston oil ring to the bottom ring groove of the piston.
13. Install the second compression ring to the middle ring groove of the piston.
14. Install the top compression ring to the top ring groove of the piston.





Notice: Use a piston ring expander to install the piston rings. The rings may be damaged if expanded more than necessary.

15. Install the piston rings.
16. Stagger the piston oil rings (2), the oil ring rail gaps (4), the second compression ring (5), and the top compression ring in relation to the notch (1) on the top of the piston.




17. Lubricate the cylinder wall and the piston rings with clean engine oil.
18. Install the piston using the J 8037 (1) and a wood handle. Guide the lower connecting rod end to prevent damaging the crankshaft journal.
19. Install the connecting rod cap and bearings. Refer to Crankshaft and Bearings Cleaning and Inspection 5. Crankshaft and Bearings Cleaning and Inspection.





Notice: Refer to Fastener Notice Fastener Notice.

20. Install the connecting rod cap bearing bolts.

Tighten the connecting rod cap bearing bolts to 35 Nm (26 lb ft). Using the J 45059 or the KM-470-B (1), tighten the bolts 1 turn of 45 degrees plus 15 degrees.

21. Install the engine block lower support bracket/splash shield bolts.

Tighten the engine block lower support bracket/splash shield bolts to 35 Nm (26 lb ft).




22. Install the oil pump/pickup tube.
23. Install the oil pump/pickup tube bolts.

Tighten the oil pump/pickup tube bolts to 8 Nm (71 lb in).

24. Install the oil pan. Refer to Oil Pan Replacement Service and Repair.
25. Install the cylinder head with the intake manifold and exhaust manifold attached. Refer to Cylinder Head Replacement Service and Repair.