Chevrolet Silverado / GMC Sierra. Manual - part 347
Fig. 405: View Of Gaging Plastic Installed On Crankshaft Journal
Courtesy of GENERAL MOTORS CORP.
IMPORTANT:
The crankshaft main bearings are a precision insert
type. Main bearing caps are machined with the engine
block, for proper clearance, and cannot be shimmed or
filed for bearing fit. If the clearances are found to be
excessive, new bearings and/or engine block and cap
repair or replacement may be required.
Do not rotate the crankshaft while gaging plastic is
between the crankshaft journal and the bearing surface.
The crankshaft bearing clearances are critical.
2008 Hummer H2
2008 ENGINE Engine Mechanical - 6.2L - H2
1. Remove the bearing caps, bearing half, and bolts. Refer to Crankshaft and Bearing
Removal.
2. Install gaging plastic onto the crankshaft journal. Install the gaging plastic the full width of
the crankshaft bearing journal.
3. Install the bearing caps, bearing half, and bolts. Refer to Crankshaft and Bearing
Installation.
4. Remove the bearing caps, bearing half, and bolts. Refer to Crankshaft and Bearing
Removal.
Excessive bearing clearance may affect crankshaft
position sensor signals and may affect OBD II system
operation.
Remove the bearing cap side bolts prior to cap removal.
2008 Hummer H2
2008 ENGINE Engine Mechanical - 6.2L - H2
Fig. 406: Measuring Gaging Plastic
Courtesy of GENERAL MOTORS CORP.
5. Using the scale supplied with the plastic gaging kit, measure the gaging plastic at its widest
area.
If the gaging plastic shows irregularity in the journal, exceeding 0.025 mm (0.001 in),
remove the crankshaft and measure the journal with a micrometer.
If clearance cannot be brought to specifications, replace the crankshaft or engine block
as required. Refer to Engine Mechanical Specifications.
Measuring Connecting Rod Bearing Clearance - Gaging Plastic Method
2008 Hummer H2
2008 ENGINE Engine Mechanical - 6.2L - H2
Fig. 407: View Of Gaging Plastic Installed On Crankshaft Journal
Courtesy of GENERAL MOTORS CORP.
1. Remove the bearing cap, bearing half, and bolts. Refer to Piston, Connecting Rod, and
IMPORTANT:
Connecting rod bearings are a precision insert type.
Connecting rods are of a powdered metal design and
cannot be shimmed or filed for bearing fit. If clearances
are found to be excessive, a new bearing and/or
connecting rod is required.
Do not rotate the crankshaft while gaging plastic is
between the crankshaft journal and the bearing surface.
2008 Hummer H2
2008 ENGINE Engine Mechanical - 6.2L - H2