Cummins/Onan — Bearing Installation
Installation · Camshaft and crankshaft bearings
From a Cummins/Onan service manual — check it applies to your exact model before use.
Applies to: Cummins/Onan MCCK
Before you start
- Avoid damaging the bearing bore during removal and installation.
Procedure
- Removal of camshaft or crankshaft bearings requires complete disassembly of engine.
- Use press or suitable plug to remove bearings. Support casting to avoid distortion; avoid damaging bearing bore.
- Use oil on bearings to reduce friction when installing and again lubricate with oil after installing.
- Camshaft: replacement bearings precision type; coat with lubricating oil.
- Place bearing on crankcase over bearing bore with lubricating hole (front only) in proper position.
- Be sure to start bearing straight. Press front bearing in flush with outside end of bearing bore.
- Press rear bearing in until past ignition plunger hole.
- Crankshaft: new main bearings precision type; before putting in main bearings, expand bearing bore by placing casting in hot water or oven heated to 200°F (93°C).
- If practical, cool precision bearing to shrink it.
- Align oil hole(s) in bearing bore; oil passage must be at least half open.
- Install cold oiled precision bearing flush with inside end of bore.
- If head of lock pin is damaged, use side cutters or Easy-Out tool to remove pin; install new lock pin.
- Apply oil to thrust washers to hold in place when crankshaft is installed.
- Oil grooves in thrust washer bearing must face crankshaft; two notches fit over lock pins.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Casting heated to 200°F (93°C) to expand bearing bore
Full service-parts list: Cummins/Onan MCCK →
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.