Crankshaft and Bearings Installation
^ Tools Required- J 36660 Torque/Angle Meter
CRANKSHAFT BEARING INSTALLATION PROCEDURE
IMPORTANT: If the crankshaft bearings have been used in a running engine, you must replace them with NEW crankshaft bearings for reassembly.
1. Clean the upper and lower crankcase crank bore with a lint-free cloth.
2. Clean all the oil from the backside of new bearing halves.
3. Install new upper crankshaft bearings into position. The thrust bearing (1) belongs in the number three journal. Be sure the upper bearing insert contains the oil transfer hole and groove. Roll the bearing into position so that the lock tang engages the crank slot. The bearing must fit flush with the upper crankcase.
4. Install new lower crankshaft bearings into position in the lower crankcase. The lower crankcase crankshaft bearings are identified by NO grooves or holes. The bearings must fit flush with the lower crankcase.
5. Apply a liberal amount of GM crankshaft prelube GM P/N 1052367 or engine oil to the upper and lower bearing surfaces.
CRANKSHAFT INSTALLATION PROCEDURE
1. Install the crankshaft sprocket drive key (1). If necessary, lightly tap the key in place with a small hammer until it bottoms on the crankshaft.
2. Gently lower the crankshaft into position in the cylinder block.
3. Make sure the crankshaft turns without binding or noise.
CRANKSHAFT BEARING CLEARANCE MEASUREMENT PROCEDURE
1. Place a length of fresh, room temperature plastic gaging material all the way across all the crankshaft bearing journals.
2. Align the lower crankcase with the dowel pins in the upper crankcase.
3. Install the lower crankcase onto the upper crankcase slowly until feeling a positive stop.
4. Inspect the upper-to-lower crankcase joint in order to make sure the lower crankcase is fully seated on the cylinder block.
5. Install the oil manifold plate.
6. Install the oil manifold plate retaining bolts. Tighten the oil manifold plate bolts to 10 Nm (89 inch lbs.).
NOTICE: Refer to Fastener Notice in Service Precautions.
7. Place the crankshaft oil scraper in position on the oil manifold. Align the holes with the main bearing bolt holes.
8. Install the main bearing bolts. The single stud-head bolt (1) used for oil pump pick-up mounting goes in the inboard position of the third set of main bearing bolts from the front of the engine.
9. Install the left side upper-to-lower crankcase perimeter bolts.
10. Install the right side upper-to-lower crankcase perimeter bolts.
11. Tighten the lower crankcase bolts in proper sequence.
11.1. First Pass
Tighten the lower crankcase bearing bolts (numbers 1 through 20) to 20 Nm(15 ft. lbs.) in the proper sequence.
11.2. Second Pass
Tighten the lower crankcase bolts (numbers 1 through 20) an additional 65° in the proper sequence using the J 36660.
11.3. Final Pass
Tighten the upper-to-lower crankcase perimeter bolts (numbers 21 through 28) to 30 Nm (22 ft. lbs.).
12. Allow the assembly to sit for at least two minutes.
13. Remove the main bearing bolts.
14. Remove the oil scraper
15. Remove the oil manifold retaining bolts and oil manifold.
16. Remove the lower crankcase.
17. Determine the main bearing clearance by comparing the width of the flattened plastic gaging material at its widest point with the graduation on the gaging material container.
18. 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 check to 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.
19. Clean the plastic gaging material from the crankshaft bearing journals using a soft lint-free cloth.