Cummins/Onan — Crosshead Adjustment
Adjustments · Crossheads
From a Cummins/Onan service manual covering: GNH-250, GNH-XI0, GNHC4, GNVH450, GV12, GV12 series, GV12-525. Check it applies to your exact model before use.
Applies to: Cummins/Onan GV12
Procedure
- Loosen crosshead adjusting screw locknut and back off one turn.
- Hold crosshead in contact with valve stem B with light finger pressure at 1/4 inch.
- Turn down adjusting screw until it touches valve stem C.
- With new crossheads, advance screw additional 20 degrees.
- With worn crossheads, advance up to 30 degrees.
- Tighten locknut to 25/30 foot-pounds.
- Check clearance between crosshead and valve spring retainer; minimum 0.020 inch.
Tools required
- wire gauge Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- locknut torque 25/30 foot-pounds
- clearance minimum 0.020 inch
Full service-parts list: Cummins/Onan GV12 →
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.