Crankshaft Main Bearing

MAIN BEARING CAPS

NOTE: Lubricate main bearing cap bolts with engine oil before installation.
The main bearing cap bolts must be tightened in the proper sequence. First the inner main cap bolts, secondly the windage tray bolts, and lastly the main cap tie (horizontal) bolts.
- Install the inside main bearing cap bolts and tighten to 20 Nm + 1/4 Turn (15 ft. lbs. + 1/4 Turn).
- Measure crankshaft end play Procedures.
- Install connecting rods and measure side clearance Service and Repair.
- Install windage tray. Lubricate bolts with engine oil and tighten to 27 Nm + 1/4 Turn (20 ft. lbs. + 1/4 turn).
- Install the main cap tie (horizontal) bolts and tighten to 28 Nm (250 in. lbs.).








STANDARD PROCEDURE - CRANKSHAFT MAIN BEARING FITTING





The grade marks for the cylinder block main bearing bore grade is located on the pan rail just below the left side engine mount bracket. These marks are read left to right, corresponding to main bore 1, 2, 3, 4.





The main bearings are "select fit" to achieve proper oil clearances. For main bearing selection, the block and crankshaft have grade identification marks.

The grade marks for the crankshaft are located on the rearmost crankshaft counter weight as shown. The crankshaft journal grade marks are read left to right, corresponding with journal number 1, 2, 3, 4.





Refer to the selection chart to properly select the main bearings. For an example, if the main bore grade is 3 and the journal grade is 2, the proper select fit bearing would be (2) +0.003 mm (+0.0002 in.).





NOTE: Service main bearings have a number from 1-5 marked in ink on the bearing surface. For verification, use the MAIN BEARING SELECTION CHART-2.7L for number to size identification.

The upper main bearing has a oil feed hole and a center groove to allow lubrication of the main journal and must be properly positioned in the block.

NOTE: Although cylinder bores are graded for size, there is only one piston size.