Cummins/Onan — Pump Belt Adjustment
Adjustments
From a Cummins/Onan operator's manual covering: 5.0 MDKUB, 6.0 MDKUB, 7.5 MDKWB, 9.0 MDKWB. Check it applies to your exact model before use.
Applies to: Cummins/Onan 5.0 MDKUB, Cummins/Onan 6.0 MDKUB, Cummins/Onan 7.5 MDKWB, Cummins/Onan 9.0 MDKWB, Cummins/Onan MDKUB, Cummins/Onan MDKWB, Kubota Z482B engine, Kubota D722B engine
Before you start
- Do not operate genset without belt guard in place.
- Operation with too much tension may cause reduced belt life.
Procedure
- Disable genset by disconnecting battery cables (negative first).
- Remove belt guard.
- Loosen bottom pivot bolt on alternator.
- Loosen bolt through long slot in alternator mounting bracket.
- Slide alternator until tension is right.
- Tighten bolts.
- Replace belt guard.
Tools required
- wrench Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Belt tension correct when 22 pounds (10 kg) finger pressure at middle of belt deflects about 0.4 inch (10 mm)
Full service-parts list: Cummins/Onan 5.0 MDKUB →, Cummins/Onan 6.0 MDKUB →, Cummins/Onan 7.5 MDKWB →, Cummins/Onan 9.0 MDKWB →, Cummins/Onan MDKUB →, Cummins/Onan MDKWB →, Kubota Z482B engine →
Source: Cummins/Onan operator's 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.