Cummins/Onan — Align Cooling System Fan Drive (Spec. A)
Adjustments · Fan drive pulleys
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
Procedure
- Use a long straightedge to align the crankshaft pulley to the fan drive pulley.
- Check for no visible gaps between straightedge and pulley surfaces.
- Mark current and estimated new fan drive pulley location on shaft.
- Remove three fan pulley bushing screws; install two into threaded holes to separate bushing.
- Move bushing to the new location mark.
- Install the 3 screws through bushing into pulley and tighten sequentially to 29 ft-lbs (39 N·m).
- Recheck alignment and repeat procedure until achieved.
- Loosen pillow block bearing mounting bolts; add shims between bearing housing and pedestal.
- Tighten bearing mounting bolts to 85 ft-lbs (116 N·m), then lockcollars to 38 ft-lbs (52 N·m).
- Rotate fan by hand; ensure minimum 1/8 inch (3 mm) fan blade tip to shroud clearance.
- Adjust fan shroud using slotted holes if clearance is insufficient.
Tools required
- Straightedge at least 48 inches (1219 mm) long Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- 29 ft-lbs (39 N·m) bushing screws
- 85 ft-lbs (116 N·m) bearing mounting bolts
- 38 ft-lbs (52 N·m) lockcollars
- Minimum 1/8 inch (3 mm) fan blade tip clearance
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.