Cummins/Onan — Engine General Disassembly

Repair & overhaul

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

Applies to: Cummins/Onan MCCK

Procedure

1. Drain crankcase oil.
2. Disconnect exhaust pipe, fuel line, battery cables, and electrical connections.
3. Remove flywheel using Onan flywheel puller.
4. Remove gear cover using care to protect oil seals from keyway damage.
5. Remove snap ring and remove crankshaft gear using gear pulling ring and gear puller.
6. Remove air cleaner, manifold assembly with carburetor and vacuum speed booster, fuel pump, fuel lines, spark plugs, ignition breaker box, etc.
7. Remove cylinder heads, oil base and oil pump.
8. Remove valves, springs, tappets, etc.
9. Remove camshaft and gear assembly.
10. Remove connecting rods, pistons and bearings.
11. Remove rear bearing plate.
12. Remove crankshaft.
13. Remove bearings as needed using correct bearing remover.

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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