Cummins/Onan — Cylinder Head Installation and Torque Sequence
Repair & overhaul
From a Cummins/Onan service manual — check it applies to your exact model before use.
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Procedure
- Install new head gasket and head assembly to cylinder block.
- Tighten cylinder head bolts finger-tight.
- Install exhaust manifold and tighten (four cylinder models only).
- Tighten cylinder head bolts in sequence to 25-30 foot-pounds (34-41 Nm).
- Tighten cylinder head bolts in same sequence to 44-46 foot-pounds (60-62 Nm).
- After 60 seconds, retighten cylinder head bolts in sequence to 44-46 foot-pounds (60-62 Nm).
- Install intake manifold, nozzles, glow plugs and oil lines.
- Install valve stem cap.
- Install push rods, rocker arms and rocker arm nuts.
- Set valve clearance.
Tools required
- Torque wrench Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Cylinder head bolt torque 44-46 ft-lb (60-62 Nm)
- Use Never-Seez, Fel-Pro C5-A or equivalent thread lubricant
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.