Check Crankshaft Bearing Clearance (With Plastigage)

Lay out plastigage.

Fig 1: Plastigage On Bearing Journal
Courtesy of GENERAL MOTORS COMPANY
NOTE:
- Crankshaft removed.
- Do not rotate the crankshaft.
Lay out plastigage (flexible plastic thread) around the entire width of the crankshaft bearing journal (1).
Install the 4 lower crankshaft bearings (3) and the lower crankshaft thrust bearing (4).

Fig 2: Crankshaft Bearing Cap Tie Plate
Courtesy of GENERAL MOTORS COMPANY

NOTE: The bolts can be reused for checking the crankshaft bearing play.
Install the crankshaft bearing cap tie plate (2).
Install the 10 inner crankshaft bearing cap tie plate bolts (1).
Tighten the 10 inner crankshaft bearing cap tie plate bolts in a sequence as shown and in the following order:

Fig 3: Inner Crankshaft Bearing Cap Tie Plate Bolts Tightening Sequence
Courtesy of GENERAL MOTORS COMPANY

CAUTION: Refer to Fastener Caution .
1. Tighten the inner crankshaft bearing cap tie plate bolts to 25 N.m (18 lb ft).
2. Tighten the inner crankshaft bearing cap tie plate bolts an additional 60°. Use EN-470-B wrench.
3. Tighten the inner crankshaft bearing cap tie plate bolts an additional 15°. Use EN-470-B wrench.
Remove the crankshaft bearing cap tie plate bolts and the crankshaft bearing cap tie plate.
Measure the crankshaft bearing play.

Fig 4: Measuring Crankshaft Bearing Play Using Measuring Scale
Courtesy of GENERAL MOTORS COMPANY

NOTE: When reading the value, do not confuse millimeters and inches on the measuring scale.
- Compare the width of the flattened plastic thread (arrow) to the measuring scale (1).
- The crankshaft bearing play should be 0.007-0.031 mm (0.00028-0.00122 in).