49. Piston, Connecting Rod, and Bearing Installation

Piston, Connecting Rod, and Bearing Installation

Piston Selection

^ Tools Required
- J 8087 Cylinder Bore Gauge
- J 36660-A Torque Angle Meter
- J 8037 Piston Ring Compressor





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.
2. Inspect the piston and the piston pin.
3. Use the J 8087 to measure the cylinder bore diameter. Measure at a point 64 mm (2.5 inch) from the top of the cylinder bore.





4. Measure the J 8087 with a micrometer and record the reading.





5. With a micrometer or caliper at a right angle to the piston, measure the piston 42 mm (1.65 inch) from the top of the piston.
6. Subtract the piston diameter from the cylinder bore diameter in order to determine piston-to-bore clearance.
7. For proper piston-to-bore clearance.
8. If the proper clearance cannot be obtained, select another piston and measure for the clearances.
9. If the proper fit cannot be obtained, hone the cylinder bore or replace the cylinder block.
10. When the piston-to-cylinder bore clearance is within specifications, mark the top of the piston using a permanent marker for installation to the proper cylinder.

Installation Procedure





1. Install the connecting rod bearings. Use the proper size bearings.
1.1. Install the bearing inserts into the connecting rod and the connecting rod cap.
1.2. Lubricate the connecting rod bearings with engine oil.
2. Install the piston and the connecting rod to the correct bore.
2.1. Slide a piece of 9.5 mm (0.375 inch) fuel or vacuum hose over the connecting rod bolts. This protects the crankshaft journal during piston and connecting rod installation.
2.2. Stagger each piston ring end gap equally around the piston.
2.3. Lubricate the piston and the piston rings with engine oil.
2.4. Install J8037Over the piston. Do not disturb the piston ring end gap location.
2.5. The piston must be installed so that the mark on the top of the piston faces the front of the engine.
2.6. Place the piston in its matching bore.
2.7. Tap the piston into its bore with a hammer handle. Guide the connecting rod to the connecting rod journal while tapping the piston into place.
2.8. Hold the J 8037 against the engine block until all the rings have entered the cylinder bore.
2.9. Remove the vacuum hose from the connecting rod bolts.

Important: Ensure that the connecting rod cap is properly oriented on the connecting rod.

3. Install the connecting rod cap.

Notice: Refer to Fastener Notice in Service Precautions.

4. Install the connecting rod bolt nuts.
4.1. Tighten the connecting rod bolt nuts to 25 Nm (18 ft. lbs.), then rotate 80 degrees using the J 36660-A.
4.2. Install the remaining connecting rods and piston assemblies.





5. Measure the connecting rod side clearance with a feeler gauge.
The correct clearance is 0.150 - 0.450 mm (0.0059 - 0.0177 inch).
6. Install the crankshaft timing sprocket with the marked side facing out and rotate the crankshaft to align the keyway with the timing mark on the engine block.