Connecting Rod Bearing: Service and Repair

REMOVAL

CAUTION: Connecting rod bearings are the precision insert type and do not use shims for adjustments. Do not file connecting rods or rod caps. If the clearances are found to be excessive, a new bearing will be required. Service bearings are available in the following sizes:
^ Standard size and 0.025 mm (0.001 inches) and 0.05 mm (0.002 inches) undersize for use with new and used standard size crankshafts.
^ 0.025 mm (0.010 inches) and 0.5 mm (0.020 inches) undersize for use with reconditioned crankshafts.
When removing a connecting rod cap, you may find a 0.025 mm (0.010 inches) undersize bearing. These are used in manufacturing for selective fitting.

1. Remove the oil pan.
2. Remove the oil pump.

CAUTION: Place numbers on the connecting rods and the connection rod caps. The connecting rod caps must be assembled with the original connecting rods.

3. Remove the connecting rod nuts.
4. Remove the connecting rod cap and the bearings.
5. Keep the bearings with the original connecting rod and the connecting rod cap for reassembly.
6. Wipe the oil from the bearings and the crankpins.
7. Inspect the bearings for excessive wear or damage.
8. Measure the crankpin for out of round and taper with a micrometer.
9. If not within specifications, replace or recondition the crankshaft.
10. If installing new bearings, determine new bearing size from the maximum crankpin diameter.
11. Measure the bearing clearance, using plastigage.
12. Place a piece of plastigage the full width of the bearing onto the crankpin.
13. The plastigage should be positioned in the middle of the bearing. The bearing is thickest in the center and the bearing clearance must be measured at this location.
14. Install the connecting rod cap with the bearing onto the connecting rod.
15. Install the connecting rod nuts.
^ On the first pass, tighten the nuts evenly to 27 Nm (20 ft. lbs.).
^ On the final pass, use the Torque Angle Meter in order to tighten the nuts an additional 55 degrees.

CAUTION: Do not turn the crankshaft with the gauging plastic installed or the accuracy of the measurement will be affected.

16. Remove the connecting rod nuts and the connecting rod cap. The plastigage will be found adhering to either the connecting rod cap or crankshaft journal. Leave the plastigage in place to measure it.
17. Measure the plastigage at its widest, using the scale provided with the plastigage.
18. If the clearance is greater than specified, select an undersize bearing and re-measure the clearance.
19. If the clearance cannot be brought to specifications, regrind the crankpin. If the crankpin is already at maximum undersize, replace the crankshaft.
20. Remove the plastigage.

INSTALLATION
1. Coat the inside surface of the bearings with the engine oil.
2. Install the connecting rod cap and the bearings.
3. Install the connecting rod nuts.
^ On the first pass, tighten the nuts evenly to 27 Nm (20 ft. lbs.).
^ On the final pass, use the Torque Angle Meter in order to tighten the nuts an additional 55 degrees.
4. Measure the connecting rod side clearance as follows:
a. When ail the connecting rod bearings have been installed, tap each connecting rod lightly parallel to the crankpin to make sure they have clearance.
b. Measure the side clearance between the connecting rod caps using a feeler gauge or dial indicator.
c. The rod side clearance should be 0.16 to 0.35 mm (0.006 to 0.014 inches).
5. Install the oil pump.
6. Install the oil pan.