Cummins/Onan — Cylinder Head Torquing
Maintenance
From a Cummins/Onan service manual — check it applies to your exact model before use.
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Procedure
- Tighten cylinder head bolts in sequence to about 15 foot-pounds.
- Repeat the sequence to a 29-31 foot-pound torque.
- Operate engine to normal hot temperature, shut off and cool to room temperature.
- Retighten bolts to same torque in same sequence.
- Perform this retightening within the first 50 hours after reassembly.
Tools required
- Torque wrench Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
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.