Cleaning And Inspection

CLEANING

CAUTION: Do not use a caustic cleaning solution or damage to connecting rods may occur.

Remove the connecting rod bearings from the connecting rods and caps. Identify each connecting rod bearing location if connecting rod bearings are to be reused. Clean the connecting rod in solvent, including the rod bore and the back of the connecting rod bearings. Blow out all passages with compressed air.

INSPECTION

CAUTION: Do not ream or hone the pin bore in the connecting rod. Replace damaged connecting rod nuts and bolts or engine damage may occur.

Inspect the connecting rods for signs of fractures and the bearing bores for out-of-round and taper. If the bore exceeds the recommended limits and/or if the connecting rod is fractured, replace it. Check the ID of the connecting rod piston pin bore. The pin bore in the connecting rod is larger than specification, install a 0.025 mm (0.001 inch) oversize piston pin. Prefit the oversize piston pin to the piston pin bore by reaming or honing the piston to provide 0.007-0.013 mm (0.0003-0.0005 inch) clearance (light slip fit). Assemble the piston, piston pin and connecting rod.

The connecting rod and related parts should be carefully inspected and checked so they conform to specifications. Various forms of engine wear caused by these parts can be readily identified.

A shiny surface on either pin boss inside of the piston usually indicates that a connecting rod is bent.

Abnormal connecting rod bearing wear can be caused by either a bent, worn or damaged crankpin or a tapered connecting rod bore.

Twisted connecting rods can create an identifiable piston skirt wear pattern, but badly twisted connecting rods will disturb the action of the entire piston, piston rings and may also cause excessive oil consumption.