Cummins/Onan — Starter Gear Lash Check
Adjustments
From a Cummins/Onan service manual — check it applies to your exact model before use.
Applies to: Cummins/Onan NHC-NHCV engine
Procedure
- Ensure starter mounting surfaces are free of dirt and oil.
- Install starter and tighten mounting bolts just enough to hold in place.
- Remove spark plugs to allow free flywheel movement.
- Manually pull starter pinion outward to fully mesh with flywheel ring gear.
- Measure free travel (lash) between pinion and ring gear teeth.
- Proper lash is 0.020 ± 0.010 in. (0.51 ± 0.25 mm).
- Loosen and adjust starter as necessary.
- Torque mounting bolts and reinstall spark plugs.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Gear lash: 0.020 ± 0.010 in. (0.51 ± 0.25 mm)
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.