Tools Required

J 36660-A  Torque Angle Meter

Important:  The crankshaft oil scraper is stamped with an arrow for the front of engine.

1. Place a length of fresh, room temperature plastic gaging material all the way across all the crankshaft bearing journals.
2. Place the crankshaft oil scraper (2) in position on the lower crankcase. Align the holes with the main bearing bolt holes.

   Important:  The crankshaft oil scraper is stamped for the location of the single stud-head bolt.

3. Place into position the main bearing bolts. The single stud-head bolt (1) is used for oil pump pick-up mounting.
   Fig 1: Installing Crankshaft Oil Scraper

   Courtesy of GENERAL MOTORS CORP.
4. Align the lower crankcase with the dowel pins in the upper crankcase.
5. Install the lower crankcase onto the upper crankcase slowly until feeling a positive stop.
6. Inspect the upper-to-lower crankcase joint to ensure that the lower crankcase is fully seated on the cylinder block.
7. Loosely install the nine lower crankcase perimeter bolts.
   Fig 2: Installing Lower Crankcase

   Courtesy of GENERAL MOTORS CORP.
   CAUTION: Refer to in FASTENER NOTICE .
8. Tighten the lower crankcase bolts (1 through 16) in proper sequence.

   Tighten 

   1. 8.1. Tighten the lower crankcase bolts in sequence to 20 N.m (15 ft lbs).
   2. 8.2. Tighten the lower crankcase bolts in sequence an additional 70 degrees using the J 36660-A. 
   Fig 3: Identifying Lower Crankcase Bolts Tightening Sequence

   Courtesy of GENERAL MOTORS CORP.
9. Tighten the lower crankcase perimeter bolts (1 through 9) in proper sequence.

   Tighten 

   Tighten the lower crankcase perimeter bolts in sequence to 30 N.m (22 ft lbs).

10. After reaching final torque, allow the assembly to sit for two minutes.
11. Remove the lower crankcase bolts.
    Fig 4: Identifying Lower Crankcase Perimeter Bolts Tightening Sequence

    Courtesy of GENERAL MOTORS CORP.
12. Remove the lower crankcase.
    Fig 5: Removing Lower Crankcase

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13. Determine the crankshaft bearing clearance by comparing the width of the flattened plastic gaging material at its widest point with the graduation on the gaging material container.

    Important:  The crankshaft bearings CAN be reused after checking the clearance if the bearings have never been used in a running engine.

Fig 6: Determining Crankshaft Bearing Clearance
Courtesy of GENERAL MOTORS CORP.
14. Compare your measurements with the Engine Mechanical Specifications . If the new bearings do not provide the proper crankshaft to bearing clearance, re-measure the crankshaft journals for the correct specified size and make sure you have the correct new bearings. If the crankshaft journals are incorrectly sized, replace the crankshaft. No crankshaft machining is permitted and undersized bearings are not available.
15. Clean the plastic gaging material from the crankshaft bearing journals with a soft, lint-free cloth.