C 1500 Suburban 2WD V8-6.5L DSL Turbo VIN F (1997)
Crankshaft Main Bearing: Testing and Inspection
CAUTION:
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The crankshaft bearing and the connecting rod journals are machined with deep, rolled fillets for strength. Grinding the crankshaft may disturb the
fillets and weaken the crankshaft. Replace the crankshaft if it is damaged.
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Perform TDC Offset Recovery procedure in Powertrain Management if the timing chain, timing gears, engine front cover, crankshaft position
sensor, crankshaft or other components affecting the timing are replaced.
1. Measure clearances using either the micrometer method or the plastic gauging method.
2. In order to measure clearances with the micrometer method, use the following procedure:
3. Install the crankshaft bearings into the crankshaft caps and engine block.
4. Install the crankshaft caps and bolts. Refer to specifications.
5. Measure the bearing inside diameter (I.D.) using an inside micrometer.
6. Measure the inside diameter with and inside micrometer. Place the micrometer at 90° to the split line of the crankshaft bearing.
7. Subtract the journal diameter from the bearing inside diameter in order to obtain the bearing clearance.
8. Clearances for crankshaft bearing numbers one, two, three, and four are 0.045-0.083 mm (0.0018-0.0033 inch).
9. Clearances for crankshaft bearing number five are 0.055-0.092 mm (0.0022-0.0037 inch).
10. If bearing clearances exceeds specifications, Install new crankshaft bearings.
11. In order to measure clearances with the plastic gauging method, use the following procedure:
12. Install all lower crankshaft bearings and the crankshaft into the block.
13. Place the gauging plastic across each crankshaft journal.
14. Install all upper crankshaft bearings and bearing caps into the block. Torque all bolts. Refer to specifications. The gauging plastic may adhere to
either the crankshaft bearing or the crankshaft journal.
15. Carefully remove all bearing caps and the upper crankshaft bearings.
