Cummins/Onan — Align Cooling System Fan Drive
Adjustments · Fan drive pulley and belt
From a Cummins/Onan service manual — check it applies to your exact model before use.
Applies to: Cummins/Onan DQKB, Cummins/Onan DQKC, Cummins/Onan QSK60 engine
Before you start
- The fan belt idler is under tension; do not allow hands between idler and belt or fan hub.
Procedure
- Use a long straightedge to align crankshaft pulley to fan drive pulley; fan pulley 0.25 inch toward engine.
- Mark current and estimated new fan drive pulley location on shaft.
- Remove two screws from fan pulley bushing; install one screw in threaded hole to separate bushing.
- Move bushing to the new location mark.
- Install the two screws into the bushing and tighten alternately to 67 ft-lbs (91 N•m) torque.
- Recheck alignment and repeat procedure until alignment is achieved.
- Install the drive belt using an 8-point socket and breaker bar to hold idler against spring tension.
Tools required
- Straightedge at least 48 inches (1219 mm) Amazon
- 8 mm hexagon wrench Amazon
- 8-point socket and breaker bar or large wrench Amazon
- Torque wrench Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Fan drive pulley 0.25 inch toward engine from straightedge
- Fan pulley bushing screws torque 67 ft-lbs (91 N•m)
Full service-parts list: Cummins/Onan DQKB →, Cummins/Onan DQKC →
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.