Connecting rod bearings for the engines covered in this guide consist of two halves or shells which are interchangeable in the rod and cap. When the shells are placed in position, the ends extend slightly beyond the rod and cap surfaces so that when the rod bolts are torqued the shells will be clamped tightly in place to insure positive seating and to prevent turning. A tang holds the shells in place.
The ends of the bearing shells must never be filed flush with the mating surface of the rod and cap.
If a rod bearing becomes noisy or is worn so that its clearance on the crank journal is excessive, a new bearing of the correct undersize must be selected and installed since there is no provision for adjustment.
Inspect the rod bearings while the rod assemblies are out of the engine. If the shells are scored or show flaking, they should be replaced. If they are in good shape check for proper clearance on the crank journal (see below). Any scoring or ridges on the crank journal means the crankshaft must be replaced, or reground and fitted with undersized bearings.
If journals are deeply scored or ridged the crankshaft must be replaced, as regrinding will reduce the durability of the crankshaft.
INSPECTION & REPLACEMENT
See Figures 1 and 2
Make sure connecting rods and their caps are kept together, and that the caps are installed in the proper direction.
Replacement bearings are available