Cummins/Onan — Generator Reassembly

Repair & overhaul

From a Cummins/Onan service manual covering: DL4, DL6, DL6T. Check it applies to your exact model before use.

Applies to: Cummins/Onan DL4, Cummins/Onan DL6, Cummins/Onan DL6T

Procedure

1. Slide the exciter rotor over the generator shaft and install the exciter lock nut; torque to 130-150 ft. lbs. (176-203 Nm).
2. Connect generator field leads to F1+ and F2- terminals; torque to 23-26 inch lbs. (2.6-2.9 Nm).
3. Press the end bearing onto the rotor shaft.
4. Place the generator fan in position on the rotor shaft.
5. Install the drive disc with the chamfer on the flywheel side; torque the 8 placement bolts to 70-80 ft. lbs. (95-108 Nm).
6. Align the holes in the drive disc and fan with the flywheel.
7. Install the 8 capscrews holding the drive disc to the engine flywheel; torque to 39 ft. lbs. (52 Nm).
8. Move the stator into position over the rotor; stator leads at 4 o'clock viewed from end bell.
9. On DL4 and DL6 sets install the 12 stator attachment capscrews; torque to 39 ft. lbs. (52 Nm). On DL6T install end bell studs in the generator adapter.
10. Install the control box assembly.
11. Apply a thin film of Molykote grease to the end bearing and end bell bearing hole mating surfaces.
12. Install the end bell with the lead opening at 4 o'clock; torque end bell stud nuts to 20 ft. lbs. (27 Nm).
13. Tap the end bell at horizontal and vertical planes and retorque the stud nuts.
14. Install the upper and lower output box brackets.
15. Plug in the control wiring harness, connect stator leads to load wires, install overspeed switch, install cover, and connect the negative battery cable.

Full service-parts list: Cummins/Onan DL6 →

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.

More Cummins/Onan repair guides →