Cummins/Onan QST30 — Permanent Magnet (PMG) Removal
Repair & overhaul
For the Cummins/Onan QST30, from the Cummins/Onan service manual.
Applies to: Cummins/Onan DFHA, Cummins/Onan DFHB, Cummins/Onan DFHC, Cummins/Onan DFHD, Cummins/Onan QST30, Cummins/Onan QST30 engine
Before you start
- The rotor assembly must not be dismantled, or magnetic properties will be destroyed.
- Highly magnetic rotor will attract stator core; avoid contact that may damage windings.
Procedure
- Disconnect negative (-) battery cable.
- HC6 Control Housing: Remove control housing grille and access covers.
- Remove three M5X12mm capscrews and lockwashers from PMG cover; remove cover.
- Disconnect PMG wiring harness connector.
- Remove four bolts and clamps retaining exciter stator housing to endbracket.
- Tap stator housing out of spigot; carefully remove from alternator endbracket.
- Remove hex head through-bolt from rotor shaft and pull complete rotor assembly.
Full service-parts list: Cummins/Onan DFHA →, Cummins/Onan DFHB →, Cummins/Onan DFHC →, Cummins/Onan DFHD →, Cummins/Onan QST30 →
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.