Cummins/Onan — Reassembling The Generator
Repair & overhaul
From a Cummins/Onan service manual — check it applies to your exact model before use.
Browse Cummins/Onan generators & specs →
Procedure
- Clean and inspect all mating surfaces.
- Coat mating area between generator bearing and end bell bearing hole with thin film of Molykote or equal.
- Install rotor-through-stud in engine crankshaft.
- Install key in crankshaft.
- Slide rotor over through-stud and onto crankshaft.
- Install air baffle.
- Install stator through-studs in adapter.
- Install stator and end bell. Torque nuts on through-studs to 19-21 ft-lbs (26-28 N·m).
- Make certain B1 lead is placed through grommet in baffle ring and out air discharge opening in adapter.
- Torque rotor-through-stud nut to 55-60 ft-lbs (75-81 N·m).
- Tap end bell to align at horizontal and vertical plane; use lead hammer to relieve stresses (recheck torque).
- Reconnect all generator leads.
- Reconnect lead B1 on adjustable resistor R21. Check B1 lead is short and kept away from blower.
- Install end bell cover.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- 19-21 SinoCMP $119.00 ft-lbs (26-28 N·m) for stator through-studs
- 55-60 ft-lbs (75-81 N·m) for rotor-through-stud nut
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.