Cummins/Onan 4.0 BF-1R/9500 — Generator Disassembly
Repair & overhaul · AC generator
For the Cummins/Onan 4.0 BF-1R/9500, from the Cummins/Onan service manual.
Browse Cummins/Onan generators & specs →
Before you start
- Do not pry end bell with a screwdriver
- Do not strike the collector rings or bearing
- Four seals must be used when reassembling or generator will overheat
Procedure
- Remove power plant from its slide rails
- Remove all accessories attached to the generator
- Tag and remove all leads
- Loosen and lift out both brush rigs
- Remove four generator through-stud nuts
- Lift or pull end bell from frame assembly (tap with plastic hammer)
- Remove frame (field) assembly, being careful not to drag on armature
- Insert square 3/8 inch drive into 12-point armature hold-down nut and remove
- Pull outward under armature and strike sharp end-wise blow on armature shaft to loosen; remove armature
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
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.