Cummins/Onan — Generator Disassembly

For these Cummins/Onan models: 4.4X, 7.7X, 8.9X, M-1641.

Applies to: Cummins Onan 8 9X, Cummins Onan M 1641

Procedure

1. Disconnect the negative (-) battery cable to prevent accidental starting.
2. Remove housing side panels as necessary to disconnect and remove load wires.
3. Disconnect lead wires from the control box and check wire markings for legibility.
4. Disconnect all engine and generator control wire leads from inside control box.
5. Remove generator end bell cover and remove the overspeed switch/sensor and bracket.
6. Attach a sling and hoist to the control cabinet, loosen fasteners securing the control housing to stator assembly.
7. Remove the generator air outlet screen, and upper and lower stator covers.
8. Remove the bracket-to-end bell mounting bolts and studs, and support bracket from skid base.
9. Attach a sling and hoist to the end bell, loosen fasteners that secure the end bell to the stator assembly.
10. Attach a sling and hoist to the stator assembly, remove the capscrews securing the stator assembly to the engine flywheel housing.
11. Install support under rotor when stator is clear.
12. Attach a sling and hoist to rotor assembly, remove capscrews securing the drive disk to engine flywheel.
13. Remove rotor assembly from engine and set on wooden blocks.
14. Perform thorough tests of all generator components while generator is disassembled.

Source: manual:943-0018 Onan UV Generator w-Torque Match-2 Regulator Service manual (10-1986).pdf. Figures and steps are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.