Detroit Diesel — Checking Bearing Clearances
Testing & diagnosis · Main and connecting rod bearings
From a Detroit Diesel service manual — check it applies to your exact model before use.
Procedure
- Remove bearing cap and wipe oil from bearing shell and crankshaft journal.
- Place plastic strip full width of bearing shell about 1/4 in off center.
- Rotate crankshaft about 30 degrees from bottom dead center and reinstall bearing cap; tighten bolts to specified torque.
- Remove bearing cap and compare flattened plastic strip width with envelope graduations.
- Measure each end of plastic to determine taper.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Source: Detroit Diesel 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.