Cummins/Onan — Engine Disassembly

Repair & overhaul

From a Cummins/Onan service manual covering: 4CCK, 5CCK, 5CCK-150R, 5CCK-3CR. Check it applies to your exact model before use.

Applies to: Cummins/Onan 4CCK, Cummins/Onan 5CCK, Cummins/Onan CCK engine

Procedure

1. Remove housings, shrouds, blower housing and air cleaner.
2. Remove flywheel using puller or pry-bar method.
3. Remove gear cover, protecting the oil seal from keyway damage.
4. Remove crank gear using puller and gear puller ring.
5. Loosen accessories such as fuel pumps, oil filter, starter and generator.
6. Remove control box and generator; lift all generator brushes and tag all wires.
7. Drain oil and discard.
8. Remove cylinder head, then valves, springs and rocker arms; then camshaft and gear, rear bearing plate, oil pump, pistons and connecting rod bearings, and crankshaft.

Full service-parts list: Cummins/Onan 4CCK →, Cummins/Onan 5CCK →

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.

More Cummins/Onan repair guides →