Cummins/Onan B43 / B48 — Timing Gear Removal and Installation

Repair & overhaul · timing gears

For the Cummins/Onan B43 / B48, from the Cummins/Onan service manual.

Applies to: Cummins/Onan B48

Procedure

1. If replacement of either the crankshaft gear or the camshaft gear becomes necessary, always install both gears new.
2. The camshaft and gear must be replaced as an assembly.
3. Before removing the camshaft and gear assembly, remove the cylinder head and valve assemblies, then the operating plunger for the breaker points and tappets.
4. To remove the crankshaft gear, first remove the snap ring and retainer washer.
5. Attach the gear pulling ring using two No. 10-32 screws.
6. Tighten the screws alternately until both are tight.
7. Attach a gear puller to the puller ring and remove the gear.
8. Each timing gear is stamped with '0' near the edge; mesh teeth so these marks exactly coincide.
9. When installing, ensure the thrust washer is properly in place behind the camshaft gear.
10. Install the crankshaft retaining washer and lock ring.

Full service-parts list: Cummins/Onan B48 →

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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