66. Piston, Connecting Rod, and Bearing Installation
Piston, Connecting Rod, and Bearing Installation- Tools Required
- J 8037 Piston Ring Compressor
- J 36660-A Torque Angle Meter
- J 41556 Connecting Rod Guide Piston Selection
Important: Measurements of all components should be taken with the components at normal room temperature. For proper piston fit, the engine block cylinder bores must not have excessive wear or taper. A used piston and pin set may be reinstalled if, after cleaning and inspection, they are within specifications.
1. Inspect the engine block cylinder bore for scoring or other damage.
2. Inspect the piston and the piston pin.
3. With the micrometer at a right angle to the piston, measure the piston.
4. Record the piston diameter.
5. Adjust the micrometer to the recorded piston diameter.
6. Insert the bore gauge into the micrometer and zero the bore gauge dial.
7. Use a bore gauge and measure the cylinder bore diameter. Measure. at a point 64 mm (2.5 inch) from the top of the cylinder bore.
8. Record the cylinder bore diameter.
9. Subtract the piston diameter from the cylinder bore diameter in order to determine the piston-to-bore clearance.
10. If the proper clearance cannot be obtained, select another piston and measure the clearances.
If the proper fit cannot be obtained, the cylinder bore may require boring and honing for an oversize piston or engine block replacement.
Installation Procedure
Important: The piston and cylinder bore have been measured and the bore has been sized for the proper clearance. Install the piston and connecting rod assembly into the proper cylinder bore. The piston alignment mark MUST face the front of the engine block.
1. Lightly lubricate the following components with clean engine oil:
- The piston
- The piston rings
- The cylinder bore
- The bearing surfaces
2. Stagger the oil control ring end gaps a minimum of 90 degrees.
3. Stagger the compression ring end gaps a minimum of 25 mm (11.0 inch).
4. Install the J 41556 to the connecting rod.
5. Install the J 8037 onto the piston and compress the piston rings.
Important: The piston alignment mark MUST facing the front of the engine block.
6. Install the piston and connecting rod assembly into the proper cylinder bore.
6.1. Hold the piston ring compressor firmly against the engine block. Using a wooden hammer handle, lightly tap the top of the piston until all of the piston rings enter the cylinder bore.
6.2. Use the J 41556 to guide the connecting rod end onto the crankshaft journal.
7. Remove the J 41556.
8. Identify the type of connecting rod bolt.
- The first design connecting rod bolt (1) can be identified by a single dimple/mark on the head of the bolt and no retaining sleeve on the bolt shank.
- The second design connecting rod bolt (2) can be identified by two dimples/marks on the head of the bolt and a retaining sleeve (3) on the bolt shank.
Notice: Refer to Fastener Notice in Service Precautions.
Important:
- When replacing connecting rod bolts, both bolts MUST be of the same design for each connecting rod assembly.
The use of different design connecting rod bolts on the same connecting rod assembly may lead to uneven clamp loads and/or connecting rod bearing bore distortion.
- Position the connecting rod cap onto the connecting rod properly. Align the flat side of the connecting rod cap with the flat side of the connecting rod.
9. Install the bearing, cap, and bolts.
9.1. Tighten the bolts a first pass evenly to 20 Nm (15 ft. lbs.).
9.2. Tighten the bolts a final pass to 85 degrees using the J 45059.
10. Inspect the connecting rods for proper orientation onto the crankshaft journal.
11. With the pistons and connecting rods installed, use a soft faced mallet and lightly tap each connecting rod assembly parallel to the crankpin to make sure that the rods have side clearance.
12. Measure the connecting rod side clearance using a feeler gauge or a dial indicator. Connecting rod side clearance should be within 0.11 - 0.51 mm (0.0043 - 0.02 inch).