Cummins/Onan — Alternator Belt Adjustment
Adjustments
From a Cummins/Onan owner's manual covering: K1800, K2000E, K38, K50, KT38, KTA38, KTA50, KTTA38, KTTA50, KtA38, KtA50, KttA38. Check it applies to your exact model before use.
Applies to: Cummins/Onan K38, Cummins/Onan K50, Cummins/Onan KTA38, Cummins/Onan KTA50, Cummins/Onan K38 and K50 engine
Before you start
- Over-tensioning of alternator belts can result in premature accessory drive bushing wear and seal leakage.
Procedure
- Loosen the alternator and adjusting link mounting capscrews.
- Loosen the jam nuts on the adjusting screw.
- Turn the adjusting screw clockwise to tighten the belt tension.
- Check the belt tension with a gauge.
- Tighten the jam nuts on the adjusting screw to 55 Nm [40 ft-lb].
- Tighten the adjusting link and alternator mounting capscrews to 55 Nm [40 ft-lb].
- Check the belt tension again.
Tools required
- GT-1293 Burroughs Tension Gauge Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Belt tension: 356 N [80 lbf]
- Jam nut / capscrew torque: 55 Nm [40 ft-lb]
Full service-parts list: Cummins/Onan K38 →, Cummins/Onan K50 →, Cummins/Onan KTA38 →, Cummins/Onan KTA50 →
Source: Cummins/Onan owner's 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.