Cummins/Onan — Connecting Rod Service

Repair & overhaul · Connecting rods

From a Cummins/Onan service manual — check it applies to your exact model before use.

Applies to: Cummins/Onan MCCK

Procedure

1. Service connecting rods at same time pistons or rods are serviced; rods must be removed with piston.
2. Replaceable bushings and bearings are used; proper clearance obtained by replacing pin bushing and bearings.
3. Rod bearings are precision size and require no reaming.
4. Install connecting rods and caps with raised lines (witness marks) aligned and caps facing toward oil base.
5. Rod and cap numbered 2 fits on crankshaft journal nearest bearing plate.
6. Coat crankshaft journal bearing surfaces with oil before installing rods.
7. Crank engine by hand to see rods are free; if necessary, rap connecting rod cap screws sharply with soft-faced hammer to set rod square.
8. Checking bearing clearance with Plastigage: place correct size Plastigage in bearing cap full width about 1/4 inch (6.35 mm) off center.
9. Rotate crank about 30 degrees from bottom dead center and reinstall bearing cap.
10. Tighten bolts to torque specified in ASSEMBLY TORQUES section. Do not turn crankshaft.
11. Remove bearing cap, leave flattened Plastigage on part, compare widest point with graduations on envelope.

Full service-parts list: Cummins/Onan MCCK →

Source: Cummins/Onan service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.

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