Crankshaft Main Bearing: Service and Repair

REMOVAL
1. Remove oil pan and windage tray. Bearing caps are not interchangeable and should be marked at removal to insure correct assembly. Upper and lower bearing halves are NOT interchangeable. Lower main bearing halves of 1, 2, 4, 5 and 6 are interchangeable. Upper main bearing halves of 1, 2, 4, 5 and 6 are interchangeable.





2. Identify main bearing caps before removal. Remove main bearing caps one at a time. Remove upper half of bearing by inserting Special Main Bearing Tool C-3059 (Fig. 102) into the oil hole of crankshaft.
3. Slowly rotate crankshaft clockwise, forcing out

CAUTION: When cleaning the gasket surfaces use a gasket remover to soften the old gasket material. Also, to avoid damage to the mating surfaces, do not use a metal scraper. Instead use a plastic or wooden corner.

INSTALLATION

NOTE: Only one main bearing should be selectively fitted while all other main bearing caps are properly tightened.

When installing a new upper bearing shell, slightly chamfer the sharp edges from the plain side.





1. Start bearing in place, and insert Main Bearing Tool C-3059 into oil hole of crankshaft (Fig. 102).
2. Slowly rotate crankshaft counterclockwise sliding the bearing into position. Remove Special Main Bearing Tool C-3059.
3. Install each main cap and tighten all bolts finger tight.
4. Tighten main cap bolts in the following torque sequence:





5. Step 1 Tighten only the center main caps bolts in the sequence order shown in (Fig. 103) to 20 Nm (15 ft. lbs.). This will seat the bearing caps onto the engine block.
6. Step 2 To ensure correct thrust bearing alignment the following procedure must be done:
7. Move crankshaft all the way to the rear of its travel.
8. Then, move crankshaft all the way to the front of its travel.
9. Wedge an appropriate tool between the rear of the cylinder block and rear crankshaft counterweight. This will hold the crankshaft in it's most forward position.
10. Step A1 Tighten the A1 bolts to 61 Nm (45 ft. lbs.) in the sequence order shown in (Fig. 103).
11. Step A2 Tighten the A2 bolts to 115 Nm (85 ft. lbs.) in the sequence order shown in (Fig. 103).
12. Step AS Tighten the AS Bolts to 54 Nm (40 ft. lbs.) in the sequence order shown in (Fig. 103).
13. Remove the holding tool.
14. Install windage tray and oil pan.