Cummins/Onan — Generator Assembly
Repair & overhaul
From a Cummins/Onan service manual covering: DL4, DL6, DL6T, DL6U. Check it applies to your exact model before use.
Applies to: Cummins/Onan DL4, Cummins/Onan DL6, Cummins/Onan DL6T
Before you start
- Disconnect negative battery cable to prevent accidental starting.
Procedure
- Grease and press end bearing onto rotor shaft.
- Place rotor fan and spacer on rotor shaft.
- Install drive disc (chamfered edge toward flywheel); tighten eight capscrews to 68 ft lbs.
- Align drive disc, fan spacer, and fan with flywheel holes.
- Secure rotor to flywheel with eight capscrews; tighten to 35 ft lbs.
- Move stator over rotor; stator leads at 3 o'clock viewed from end bell.
- Install thirteen capscrews in stator attachment ring; tighten to 35 ft lbs.
- Remove blocking and lower generator onto rear vibration isolators.
- Install air discharge screening and connect grounding strap.
- Install capscrew, locking washer, flat washer in each vibration isolator.
- Apply MolyKote grease to end bearing and end bell bearing hole.
- Install end bell with stator lead opening at 3 o'clock using four capscrews.
- Install bearing retainer with four capscrews; tighten to 4.5 ft lbs.
- Install exciter rotor (connect F1, F2) and exciter stator; tighten to 4.5 ft lbs.
- Install overspeed switch assembly; tighten to 53 ft lbs; mount output box; tighten to 20 ft lbs.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- 68 ft lbs (92 N-m) drive disc
- 35 ft lbs (48 N-m) rotor to flywheel
- 35 ft lbs (48 N-m) stator ring
- 4.5 ft lbs (6 N-m) bearing retainer
- 53 ft lbs (72 N-m) overspeed switch
- 20 ft lbs (27 N-m) output box
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.