Connecting Rod Bearing: Service and Repair

Inspecting or replacement of connecting rod bearings requires removal of the engine assembly from the chassis. Clearance between the connecting rod bearing and the crankshaft journal can be measured with the aid of plastic gauging material as follows:


REMOVE OR DISCONNECT
1. With engine on engine stand. remove oil pan and oil pickup as described in this section.

NOTE: Old bearings with run time should never be reused. If a rod cap is removed. always replace the bearings. However. new bearings should be plastic gauged. Powdered metal rods use rod bolts which arc designed to yield when torqued. Thus the bolts must be replaced whenever a rod cap is removed.

IMPORTANT
1. When installing connecting rods into engine, be sure to apply a generous coat of Crankshaft Prelube. part number 1052367 to the crankshaft journals.
2. Remove oil scraper by removing nine remaining retainer nuts.
3. Rotate crankshaft until bearing to be measured is most accessible in crankcase opening.
4. Remove bearing cap and wipe oil from crankshaft journal and bearing insert.
5. Place a piece of plastic gaging material in center of cap.

IMPORTANT
^ When using plastic gaging material. plastic material and part being measured must both be at room temperature. IF parts are excessively warm, an incorrect reading may result. Fresh plastic gaging material is recommended for greatest accuracy.

6. Reinstall bearing cap. Tighten nuts to 25 Nm +110° (18 lb. ft. + 110°).

IMPORTANT
^ It is extremely important to position tangs on bearings in notches in rod and cap or both could be damaged.

Checking Bearing Clearance:

7. Remove bearing cap and determine clearance by comparing width of flattened plastic gaging material. at its widest point. with graduations on plastic gaging material container. Number within matching graduation on envelope indicates clearance.

MEASURE
^ If clearance is greater than 0.003 inch (0 076 mm), replace bearing. If new bearings do not reduce clearance to less than 0.003 inch (0 076 mm), crankshaft must be replaced to obtain specified limits. If both new bearings and new crankshaft are installed. clearance should be from 0.001 inch to .0028 inch (0.025 mm to 0.071 mm).

8. Repeat procedure as necessary for remaining bearings.