Cummins/Onan 3.6MKY / 4MKY — Rotor Bearing Replacement
Repair & overhaul
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
- Do not heat rotor bearing for removal or installation.
Procedure
- Measure and record the distance between the bearing and the collector ring assembly.
- Use a small puller or arbor press to remove the bearing; cover the rotor shaft end with a steel plate.
- Inspect the rotor shaft for dirt or corrosion; clean with emery cloth if necessary.
- Place the rotor, engine end down, in an arbor press on a flat steel plate.
- Press the new bearing (inner race only) onto the shaft to the recorded distance.
- Check the bearing seal for damage after installation.
Tools required
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.