Connecting Rod and Bearing-Fitting

CONNECTING ROD BEARING CLEARANCE
Engine connecting rod bearing clearances can be determined by use of Plastigage or equivalent. Replacement bearings are available in the standard size and the following undersizes: 0.025 mm (0.001 inch) and 0.250 mm (0.010 inch). The following is the recommended procedure for the use of Plastigage:
1. Rotate the crankshaft until the connecting rod to be checked is at the bottom of its stroke.
2. Remove oil film from surface to be checked. Plastigage is soluble in oil.
3. Place a piece of Plastigage across the entire width of the bearing shell in the bearing cap approximately 6.35 mm (1/4 inch) off center and away from the oil hole. In addition, suspect areas can be checked by placing Plastigage in that area.
4. Assemble the rod cap with Plastigage in place. Tighten the rod cap to 27 Nm (20 ft. lbs.). Do not angle torque bolts the additional 1/4 turn, at this time.

NOTE: Do not rotate the crankshaft while assembling the cap or the Plastigage may be smeared, giving inaccurate results.





Fig. 21

5. Remove the bearing cap and compare the width of the flattened Plastigage (Fig. 21) with the scale provided on the package. Locate the band closest to the same width. This band indicates the amount of oil clearance. Differences in readings between the ends indicate the amount of taper present. Record all readings taken. Refer to Engine; Specifications. Plastigage generally is accompanied by two scales. One scale is in inches, the other is a metric scale. If the bearing clearance exceeds wear limit specification, replace the bearing.

CONNECTING ROD SIDE CLEARANCE
1. Before installing the NEW bolts the threads should be oiled with clean engine oil.

NOTE: The connecting rod bolts should not be reused.

2. Install each bolt finger tight than alternately torque each bolt to assemble the cap properly.
3. Tighten the bolts to 27 Nm PLUS 1/4 turn (20 ft. lbs. PLUS 1/4 turn) Do not use a torque wrench for last step.





Fig. 22

4. Using a feeler gauge, check connecting rod side clearance (Fig. 22). Refer to Engine; Specifications for connecting rod specifications.