Cummins/Onan — Generator assembly (revolving field)
Repair & overhaul · AC generator
From a Cummins/Onan service manual covering: 10.0JC, 12.5JC, 15.0JC, 4.0JB, 5.0JB, 6.0JB, 6.1JB, 7.5JB, 7.6JB. Check it applies to your exact model before use.
Applies to: Cummins/Onan 10.0JC, Cummins/Onan 12.5JC, Cummins/Onan 15.0JC, Cummins/Onan 5.0JB, Cummins/Onan 6.0JB, Cummins/Onan 6.1JB, Cummins/Onan 7.5JB, Cummins/Onan 7.6JB, Cummins/Onan JB engine, Cummins/Onan JC engine
Procedure
- Clean and inspect all mating surfaces
- Coat mating area between generator shaft and engine crankshaft with a thin film of lubricating oil
- Install the rotor-through-stud in the engine crankshaft and install the key
- Slide the rotor over the through-stud and onto the crankshaft
- Install the baffle ring and generator through studs in the adapter
- Install the stator and bearing support (end bell) and tighten nuts on through-studs
- Torque down the rotor-through-stud nut (55-60 ft. lb.)
- Install the brushes and brush holders, close the Magneciter and install end cover
Tools required
- torque wrench Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- 55-60 ft. lb. rotor-through-stud nut
Full service-parts list: Cummins/Onan 10.0JC →, Cummins/Onan 12.5JC →, Cummins/Onan 15.0JC →, Cummins/Onan 5.0JB →, Cummins/Onan 6.0JB →, Cummins/Onan 6.1JB →, Cummins/Onan 7.5JB →, Cummins/Onan 7.6JB →
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.