Micrometer Method for Crankshaft Bearings
WARNING: This page is about a different car, the 2005 GMC Yukon XL, 2005 Chevrolet Suburban, and 2005 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
- Measure the crankshaft main journal diameter with a micrometer in several places along the length approximately 90 degrees apart, minimum of 4 places, and average the measurements.
- Determine the taper and the out-of-round. Refer to Engine Mechanical Specifications .
- Install the NEW crankshaft bearings into the crankshaft bearing caps and the engine block.
- Install the bearing cap bolts and studs.
Tighten:
- Tighten the bearing cap 1-5 inner bolts a first pass to 30 N.m (22 lb ft).
- Tighten the bearing cap 1-5 outer studs a first pass to 30 N.m (22 lb ft).
- Tighten the bearing cap 1-5 inner bolts a final pass an additional 90 degrees using the J 45059 .
- Tighten the bearing cap 1-5 outer studs a final pass an additional 80 degrees using the J 45059 .
- Measure the crankshaft bearing inside diameter (ID) using an inside micrometer. Measure at a minimum of four places and average the measurements.
- In order to determine the crankshaft bearing clearance, subtract the crankshaft journal diameter from the crankshaft bearing ID.
- Compare the crankshaft bearing clearance to the specifications. Refer to Engine Mechanical Specifications .
- If the crankshaft bearing clearances exceeds specifications, install undersize crankshaft bearings to achieve the correct clearance.
- Measure the new crankshaft bearing inside diameter (ID) using an inside micrometer.
- Replace the crankshaft if the proper clearances cannot be obtained with standard size bearings.
IMPORTANT:
When bearings are removed, NEW bearings must be installed during reassembly.
NOTE:
Refer to Fastener Notice
in Cautions and Notices.
IMPORTANT:
Tighten the inner crankshaft bearing cap bolts before tightening the outer crankshaft bearing cap studs.