Cummins/Onan QST30 — Crosshead Adjustment
Adjustments
For the Cummins/Onan QST30, from the Cummins/Onan owner's manual.
Applies to: Cummins/Onan G-Drive, Cummins/Onan QST30, Cummins/Onan QST30 engine
Before you start
- The adjusting screw must not turn when the lock nut is tightened.
Procedure
- Adjust crossheads before adjusting valves, on the cylinder with both valves closed.
- Loosen the crosshead adjusting screw locknuts on intake and exhaust.
- 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 valve stem top without raising the crosshead.
- Hold the screw and tighten the locknut to the specified torque.
- Torque value with adapter ST669: 45 N-m [35 ft-lb].
- Torque value without adapter: 60 N-m [45 ft-lb].
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- With adapter 45 N-m [35 ft-lb]
- Without adapter 60 N-m [45 ft-lb]
Full service-parts list: Cummins/Onan QST30 →
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.