Measuring Crankshaft Bearing Clearances - Plastic Gage Method

WARNING: This page is about a different variant/trim than selected.

Fig 1: View Of Crankshaft Bearings At Engine Block

Courtesy of GENERAL MOTORS CORP.

Fig 2: Crankshaft

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Fig 3: Installing Gaging Plastic

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Fig 4: Crankshaft Bearings

Courtesy of GENERAL MOTORS CORP.

Fig 5: Crankshaft Bearing Caps

Courtesy of GENERAL MOTORS CORP.

Install the crankshaft bearing caps in the original positions and with the arrow on the crankshaft bearing caps in the direction of the front of the engine block.

NOTE: Refer to Fastener Notice in Cautions and Notices.

Install the crankshaft bearing cap bolts.
Tighten: Tighten the crankshaft bearing caps to 105 N.m (77 lb ft).
Remove the crankshaft bearing cap bolts.
Remove the crankshaft bearing caps. The gaging plastic may adhere to either the crankshaft bearing journal or the crankshaft bearing surface.

Fig 6: Measuring Compressed Width

Courtesy of GENERAL MOTORS CORP.

Without removing the gaging plastic, measure the compressed width at the widest point using the graduated scale on the edge of the gaging plastic envelope.
If the flattened gaging plastic tapers toward the middle or the ends, there may be a difference in clearance indicating taper, low spot or other irregularity of the crankshaft bearing or the crankshaft bearing journal.
Remove the flattened gaging plastic.
Measure the remaining crankshaft bearing journals.