Main Bearing Clearance Inspection
- Remove the main bearing caps and the bearing halves (see CRANKSHAFT AND PISTON REMOVAL ).
- Clean each main journal and bearing half with a clean shop towel.
- Place one strip of plastigage across each main journal.NOTE: If the engine is still in the vehicle when you bolt the main cap down to check the clearance, the weight of the crankshaft and the drive plate will flatten the plastigage further than just the torque on the cap bolt and give you an incorrect reading. For an accurate reading, support the crank with a jack under the counterweights, and check only one bearing at a time.
- Reinstall the bearings and the caps, then tighten the bearing cap bolts to 74 N.m (7.5 kgf.m, 54 lbf.ft), and the bearing cap side bolts to 49 N.m (5.0 kgf.m, 36 lbf.ft) in the proper sequence (see step 23 on CRANKSHAFT AND PISTON INSTALLATION ).NOTE:
- Apply new engine oil to the bolt threads and flanges.
- Do not rotate the crankshaft during inspection.
- Remove the cap and the bearing half, and measure the widest part of the plastigage.
Main Bearing-to-Journal Oil Clearance
Standard (New): 0.019-0.045 mm
(0.0007-0.0018 in.)
Service Limit: 0.050 mm (0.0020 in.)
- If the plastigage measures too wide or too narrow, remove the crankshaft, and remove the upper half of the bearing. Install a new, complete bearing with the same color code, and recheck the clearance. Do not file, shim, or scrape the bearings or the caps to adjust clearance.
- If the plastigage shows the clearance is still incorrect, try the next larger or smaller bearing (the color listed above or below the current one), and check again. If the proper clearance cannot be obtained by using the appropriate larger or smaller bearings, replace the crankshaft and start over (see CRANKSHAFT AND PISTON REMOVAL ).