Crankshaft Bearing Selection Plastic Gage Method

Tools Required 

J 45059  Angle Meter

1. Clean the cylinder block bearing fitting surfaces.
2. Clean the crankshaft and upper bearings (1) and lower bearings (2).
Fig 1: View Of Upper & Lower Bearings
Courtesy of GENERAL MOTORS CORP.
3. Install the bearings into the cylinder block and the bearing caps.
Fig 2: View Of Crankshaft
Courtesy of GENERAL MOTORS CORP.
4. Install the crankshaft into the cylinder block.
5. Rotate the crankshaft approximately 30 degrees to seat the bearings.
6. Place the plastic gage over the crankshaft journal across the full width of the bearing. Note: Do not allow the crankshaft to rotate at any time during bearing cap installation and tightening or the plastic gauge measurement will be inaccurate.
Fig 3: View Of Plastic Gage Over Crankshaft Journal
Courtesy of GENERAL MOTORS CORP.
7. Install the crankshaft bearing caps.
Fig 4: View Of Crankshaft Bearing Caps
Courtesy of GENERAL MOTORS CORP.
NOTE: Refer to Fastener Notice in Cautions and Notices.
8. Install the crankshaft bearing cap bolts.
9. Tighten the crankshaft bearing cap bolts in the proper sequence.

   Tighten: 

   • 1st step 98 N.m (72 lb ft).
   • 2nd step 132 N.m (97 lb ft).
   • 3rd step 30 degrees using J 45059  .

Fig 5: Crankshaft Bearing Cap Bolts Tightening Sequence
Courtesy of GENERAL MOTORS CORP.
10. Install the crankshaft bearing cap side bolts.

    Tighten:  Tighten the crankshaft bearing cap side bolts in the proper sequence to 70 N.m (52 lb ft).

Fig 6: View Of Crankshaft Bearing Cap Side Bolts
Courtesy of GENERAL MOTORS CORP.
11. Remove the crankshaft bearing cap bolts.
12. Remove the crankshaft bearing caps.
13. Compare the width of the plastic gauge with the scale printed on the plastic gauge container.
Fig 7: View Of Plastic Gauge W/Scale Printed
Courtesy of GENERAL MOTORS CORP.
14. Select the crankshaft bearing grade that provides the proper oil clearances. The production specification for crankshaft bearing clearance is 0.039-0.070 mm (0.0015-0.0028 in) and the service limit is 0.014 mm (0.0055 in).