Cummins/Onan — Angular Alignment Procedure (750 kW gensets and larger)
Adjustments · generator/engine coupling
From a Cummins/Onan service manual — check it applies to your exact model before use.
Applies to: Cummins/Onan DFGB, Cummins/Onan DFGE, Cummins/Onan DFLB, Cummins/Onan DFLC, Cummins/Onan DFLE, Cummins/Onan VTA28-G5 engine, Cummins/Onan KTA50 engine
Before you start
- Accidental starting during this procedure presents hazard of severe injury or death
- Do not bar engine over by prying on fan blade
Procedure
- Disconnect negative battery cable(s) before beginning
- Fasten dial indicator to generator shaft or cooling fan, sensing point on capscrew head or drive disc flat surface
- Bar engine over in clockwise rotation as viewed from flywheel, do not allow roll-back at end of travel
- Record total indicator reading (T.I.R.) as sum of max positive and negative readings over one revolution
- Calculate shim correction using ratio of generator shaft-to-indicator distance vs generator mounting bolt distance
- Add or remove shims from both generator mounting feet as calculated
Tools required
- dial indicator Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Maximum T.I.R. should not exceed .001 inch per inch of radius (center of shaft to indicator axis)
Full service-parts list: Cummins/Onan DFGB →, Cummins/Onan DFGE →, Cummins/Onan DFLB →, Cummins/Onan DFLC →, Cummins/Onan DFLE →
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.