Cummins/Onan — Crossheads - Adjustment
Adjustments · Valve crossheads
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
Procedure
- Adjust the crossheads on the cylinder that has both valves closed.
- Loosen the crosshead adjusting screw locknuts on the intake and exhaust valve crossheads.
- Turn the adjusting screw out at least one turn.
- Hold the crosshead down against its guide.
- Turn the adjusting screw in until it touches the top of the valve stem but does not raise the crosshead.
- Hold the adjusting screw and tighten the lock nut to the torque value.
Tools required
- ST-669 Torque Wrench Adapter Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Crosshead lock nut torque with ST-669 Amazon eBay $204.59 adapter: 35 Nm [25 ft-lb]; without adapter: 40 Nm [30 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.