70. Piston, Connecting Rod, and Bearing Installation
Piston, Connecting Rod, and Bearing Installation
Special Tools
* J 8037 - Piston Ring Compressor
* J 8087 - Cylinder Bore Gauge
* J 41556 - Connecting Rod Guide
* J 45059 - Angle Meter
For equivalent regional tools, refer to Special Tools Special Tools.
Piston Selection
Note:
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, pin, and connecting rod assembly may be installed if, after inspection is within specifications.
1. With a micrometer at a right angle, measure the piston outside diameter (OD). Measure the diameter 43 mm (1.69 in) from the top of the piston. Refer to Engine Mechanical Specifications (L77) Service Limits & General Specifications.
2. Record the piston OD.
3. Adjust the micrometer to the recorded piston OD.
4. Insert the J 8087 - bore gauge into the micrometer and zero the gauge dial.
5. Using the J 8087 - bore gauge, measure the cylinder bore inside diameter (ID). Measure at a point 64 mm (2.5 in) from the top of the cylinder.
6. Record the cylinder bore ID.
7. Subtract the piston OD from the cylinder bore ID in order to determine the piston-to-bore clearance. Refer to Engine Mechanical Specifications (L77) Service Limits & General Specifications.
8. If the proper clearance cannot be obtained, select another piston and pin assembly and measure the clearances again. If the proper fit cannot be obtained, the cylinder bore may require honing for an oversize piston.
Piston, Pin, and Connecting Rod Installation
1. Lubricate the following components with clean engine oil:
* Piston
* Piston rings
* Cylinder bore
* Bearings and bearing surfaces
2. Install the bearings to the connecting rod and cap.
3. Position the oil control ring end gaps a minimum of 25 mm (1.0 in) from each other.
4. Position the compression ring end gaps 180 degrees opposite each other.
5. Install the J 41556 - rod guide to the connecting rod.
6. Identify the proper installation direction of the piston and connecting rod assembly. When installing the piston and connecting rod assembly, the mark on the top of the piston (1) and the large tabs (2) on the side of the connecting rod should face the front of the engine.
7. Install the J 8037 - ring compressor onto the piston and compress the piston rings.
Note:
The piston alignment mark MUST face the front of the engine block.
8. Install the piston, pin, and connecting rod assembly into the cylinder bore. Hold the piston ring compressor firmly against the engine block. Using a wooden hammer handle, lightly tap the top of the piston until all piston rings have entered the cylinder bore.
9. Use the J 41556 - rod guide to guide the connecting rod onto the crankshaft journal.
10. Remove the J 41556 - rod guide from the connecting rod.
Caution:
Refer to Fastener Caution Fastener Caution.
Note:
* The connecting rod and cap must be assembled with the mating surfaces properly aligned.
* If re-using connecting rods, DO NOT re-use connecting rod fasteners. During an installation procedure, the new connecting rod bolts can be re-tightened a maximum of 3 times.
11. Install the bearing cap (103), bearing (104), and bolts (102).
1. Tighten the bolts a first pass to 20 Nm (15 lb ft).
2. Tighten the bolts a final pass to 85 degrees using the J 45059 - angle meter.
12. Measure the connecting rods for the proper side clearance. Refer to Engine Mechanical Specifications (L77) Service Limits & General Specifications.