Crankshaft Main Bearing: Testing and Inspection

Checking Clearance With Plastigage:

1. To check main bearing to journal oil clearance, remove the main caps and bearing halves.
2. Clean each main journal and bearing half with a clean shop towel.
3. Place one strip of plastigage across each main journal.

NOTE: If the engine is still in the car when you bolt the main cap down to check clearance, the weight of the crank and flywheel 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.

4. Reinstall the bearings and caps, then torque the bolts. 75 Nm (7.5 kg-m, 54 lb ft)

NOTE: Do not rotate the crank during inspection.

5. Remove the cap and bearings again, and measure the widest part of the plastigage.

Main Bearing Oil Clearance:
No. 1, 2:
Standard (New): 0.021 - 0.045 mm (0.0008 - 0.0018 in)
Service Limit: 0.050 mm (0.0020 in)
No. 3:
Standard (New): 0.025 - 0.049 mm (0.0010 - 0.0019)
Service Limit: 0.054 mm (0.0021 in)
No. 4:
Standard (New): 0.013 - 0.037 mm (0.0005 - 0.0015 in)
Service Limit: 0.050 mm (0.0020 in)
No. 5:
Standard (New): 0.009 - 0.033 mm (0.0004 - 0.0013 in)
Service Limit: 0.050 mm (0.0020 in)

6. If the plastigage measures too wide or too narrow, (remove the engine if it's still in the car), remove the crank, and remove the upper half of the bearing from the block. Install a new, complete bearing with the same color code, and recheck the clearance.

CAUTION: Do not file. shim, or scrape the bearings or the caps to adjust clearance.

7. If the plastigage shows the clearance is still incorrect, try the next larger or smaller bearing (the color listed above or below that one), and check again.

NOTE: If the proper clearance cannot be obtained by using the appropriate larger or smaller bearings, replace the crank and start over.