Cummins/Onan — Generator Disassembly

For these Cummins/Onan models: 04SXINIA, 102SXIN1A, 208, 2SX5IN, 2SXIN, J-Series, O6SXIN1A, O7SXIN1A.

Applies to: Cummins Onan 04Sxinia, Cummins Onan 102Sxin1A, Cummins Onan 2Sx5In, Cummins Onan 2Sxin, Cummins Onan J Series, Cummins Onan O6Sxin1A, Cummins Onan O7Sxin1A

Procedure

1. Disconnect the battery to prevent accidental starting of the set.
2. Remove the exciter cover and open the exciter. This will reveal the rotor-thru-stud nut.
3. Remove the four machine screws on the end bell near the bearing and lift out the brush holders.
4. Remove the lead from the tapped adjustable resistor in the generator air outlet opening.
5. Remove the leads from the control box to the ignition system choke, start disconnect switch, etc. on the engine.
6. Remove generator-through-stud nuts, remove the end bell and stator assembly.
7. Use screwdriver slots in the adapter to pry the stator loose. Be careful not to let the stator touch or drag on the rotor.
8. Remove baffle ring from adapter.
9. Turn rotor-through-stud nut to the end of the through stud.
10. While pulling the rotor outward with one hand, strike a sharp blow to the nut (in the direction of the through stud, not vertically) with a heavy, soft-faced hammer to loosen the rotor from its tapered shaft fit.
11. If the rotor does not come loose, strike it with a sharp downward blow in the center of the lamination stack with a lead or plastic hammer.
12. Rotate the rotor and repeat until it comes loose.
13. Be careful not to hit the collector rings, bearings or windings.
14. After disassembly, all parts should be wiped clean and visually inspected.

Source: manual:Onan Magneciter Service- SECTION 4. REVOLVING FIELD GENERATORS.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.