Cummins/Onan — Valve Clearance Adjustment (RDJE)
Adjustments · valve train
From a Cummins/Onan service manual — check it applies to your exact model before use.
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Procedure
- Rotate flywheel clockwise until cylinder number 1 is up on compression stroke and the TC mark aligns with the timing pointer.
- Turn 10-45° past TC to be sure the lifter moves off the cam ramp.
- Adjust both intake and exhaust valves to 0.017 inch (0.43 mm).
- Using a feeler gauge, check clearance between rocker arm and valve.
- Adjust with the lock nut securing rocker arm to the cylinder head.
- Repeat for number 2 cylinder.
Tools required
- Feeler gauge Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Valve clearance 0.017 inch (0.43 mm), cold
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.