Crankshaft Main Bearing: Testing and Inspection

ORIENTATION OF CRANKSHAFT BEARING CAPS





- Main bearing cap -1- at oil pump end (front)
- Main bearing cap -4- at flywheel end (rear)

CAUTION: Bearing shells must be reinstalled in their original location and orientation. Always label the bearing shells according to their installed position before removing. NEVER interchange used bearing shells.

CHECKING AXIAL CLEARANCE





- Install dial indicator with holder VW387 on oil pump and set indicator against crankshaft counterweight.
- Push crankshaft (longitudinally) toward dial indicator by hand.
- Set dial gauge to zero.
- Push crankshaft away from dial indicator and read gauge.
Specifications:
- New: 0.07-0.23 mm (0.0027-0.0091 inch)
- Wear limit: 0.25 mm (0.0098 inch)

CHECKING RADIAL CLEARANCE

NOTE: Radial clearance is measured using Plastigage.

- Remove crankshaft bearing cap.
- Clean bearing shell and crankshaft journal.





- Place Plastigage on crankshaft journal over entire width of bearing, or in bearing shell (arrow).

Plastigage Type:
PG-1 (Green)
Measuring range: 0.025 - 0.076 mm
PR-1 (Red)
Measuring range: 0.050 - 0.150 mm

- Install crankshaft bearing cap with bearing shell and new bolts.
- Tighten to 60 Nm (44 ft. lbs.) plus 1/2 turn (180°).

CAUTION: DO NOT turn the crankshaft or allow it to rotate during the measurement with Plastigage in place.

- Remove crankshaft bearing cap again.





- Determine width of Plastigage and corresponding thickness using measuring scale provided.
Specifications:
- New: 0.018-0.045 mm (0.0007-0.0018 inch)
- Wear limit: 0.10 mm (0.0039 inch)