Facts About Generators
GeneratorsDirectoryCompareRepairEnginesControllersPartsManufacturersGuides
Search models or part #
Home›Repair guides›Cummins/Onan›Valve Lash (Clearance) Adjustment

Cummins/Onan 3.6MKY / 4MKY — Valve Lash (Clearance) Adjustment

Adjustments · Valve system

For the Cummins/Onan 3.6MKY / 4MKY, from the Cummins/Onan service manual.

Applies to: Cummins/Onan 3.6MKY, Cummins/Onan 4MKY

Before you start

  • Adjust valve clearance only when engine is at ambient temperature

Procedure

  1. Remove head cover; inspect valve stems for alignment with rocker arms.
  2. Advance engine until both valves are closed and no pressure on lifters (piston at TDC).
  3. Check clearance with feeler gauge between valve stem top and rocker arm.
  4. Loosen outer locking nut and turn adjusting nut as needed to obtain correct clearance.
  5. Tighten locking nut after adjustment.
  6. Recheck valve clearance and check rocker arm bolts have not loosened.
  7. Reinstall head cover and torque bolts.

Tools required

Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.

Specs & values

  • Intake and exhaust valve lash 0.002 inch (0.05 mm) cold

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.

More Cummins/Onan repair guides →