Cummins/Onan 3.6MKY / 4MKY — Piston and Crankshaft Removal
Repair & overhaul · Engine block
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
- Improper use of a ridge reamer can damage the cylinder bore
Procedure
- Remove carbon from top of cylinder bore and check for ridge; remove ridge with a ridge reamer.
- Remove the two bolts from the connecting rod cap; mark direction of assembly.
- Remove rod cap and push piston assembly out the top of the cylinder.
- Carefully pull the crankshaft out of the oil seal and bearing.
Tools required
- Ridge reamer Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Connection rod bolts 18-20 FridayParts $25.20 lb-ft (24-27 N-m)
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.