Crankshaft Bearing Clearance Measurement Procedure
WARNING: This page is about a different variant/trim than selected.
- Place a length of fresh, room temperature plastic gaging material all the way across all the crankshaft bearing journals.
- Align the lower crankcase with the dowel pins in the upper crankcase.
- Install the lower crankcase onto the upper crankcase slowly until feeling a positive stop.
- Inspect the upper-to-lower crankcase joint in order to make sure the lower crankcase is fully seated on the cylinder block.
- Install the old oil manifold and oil scraper plate assembly.
- Install the oil manifold plate bolts.
Tighten: Tighten the oil manifold plate bolts to 10 N.m (89 lb in).
- Loosely install the main bearing bolts. The single stud-end bolt (1) used to attach the oil pump pipe and screen assembly support bracket is installed in the inboard position in the second set of main bearing bolts from the front and left bank side of the engine.
- Install the left side upper-to-lower crankcase perimeter bolts.
- Install the right side upper-to-lower crankcase perimeter bolts.
- Tighten the lower crankcase bolts in proper sequence.
- First Pass
Tighten: Tighten the lower crankcase bearing bolts (1-20) to 20 N.m (15 lb ft) in the proper sequence.
- Final Pass
Tighten: Tighten the lower crankcase bolts (1-20) an additional 65 degrees in the proper sequence using the J 45059 .
- First Pass
- Tighten the upper-to-lower crankcase perimeter bolts (1-8).
Tighten: Tighten the upper-to-lower crankcase perimeter bolts (1-8) to 30 N.m (22 lb ft).
- Allow the assembly to sit for at least 2 minutes.
- Remove the main bearing bolts (1).
- Remove the oil manifold plate bolts.
- Remove the old oil manifold and oil scraper plate assembly.
- Working on either side of the lower crankcase, separate the crankcase halves by alternately prying in the grooves provided until the lower crankcase is free of the dowel pins.
- Remove the lower crankcase.
- Determine the main bearing clearance by comparing the width of the flattened plastic gaging material at its widest point with the graduation on the gaging material container.
- Compare your measurements with the engine mechanical specifications. If the new bearings do not provide the proper crankshaft to bearing clearance, re-measure the crankshaft journals for the correct specified size and check to make sure you have the correct new bearings. If the crankshaft journals are incorrectly sized, replace the crankshaft. No crankshaft machining is permitted and undersized bearings are not available.
- Clean the plastic gaging material from the crankshaft bearings and/or crankshaft bearing journals using a soft lint-free cloth.
- Coat the upper crankshaft bearings and crankshaft main bearing journals with GM crankshaft prelube GM P/N 1052367, (Canadian P/N 992869), or equivalent.
- Reinstall the crankshaft into position in the cylinder block.
NOTE:
Refer to Fastener Notice
in Cautions and Notices.
NOTE:
Use a plastic pry tool when prying case halves apart to prevent damage to the Upper and Lower Crankcase surface. Do not continue to push the pry tool in the crankcase as the Upper and Lower Crankcase halves separate. This may damage the sealing surface.