Cummins/Onan B43 / B48 — Starter Mounting and Gear Lash Adjustment
Installation · starting system
For the Cummins/Onan B43 / B48, from the Cummins/Onan service manual.
Applies to: Cummins/Onan B48
Before you start
- Failure to torque starter bolts properly can cause starter failure and ring gear damage.
Procedure
- Make sure the starter mounting surface on the engine base is clean and free of oil.
- Install starter motor and tighten mounting capscrews just enough to hold starter in place.
- Remove spark plugs from the engine to allow free movement of the flywheel.
- Manually pull the starter pinion gear outward until pinion gear teeth mesh completely with flywheel ring gear teeth.
- Measure the amount of free travel (lash) between pinion gear teeth and ring gear teeth.
- Adjust starter motor as necessary to obtain proper lash; if lash is tight causing binding, or greater than 0.035 inch (0.889 mm), adjust.
- Remove flywheel, and torque starter mounting capscrews to 24 to 26 ft-lbs (33 to 35 Nm).
- Install flywheel, spark plugs, blower housing, and cylinder air housings.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Proper lash 0.020 +/- 0.010 inches (0.51 +/- 0.25 mm)
- Maximum lash 0.035 inch (0.889 mm)
- Starter mounting capscrews 24 to 26 ft-lbs (33 to 35 Nm)
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.