Crankshaft Main Bearing

CYLINDER BLOCK






CRANKSHAFT MAIN BEARING JOURNALS






MAIN BEARING CAP TORQUE AND SEQUENCE

NOTE: Lubricate main bearing cap bolts with engine oil before installation.

1. Install each main cap and tighten bolts finger tight.
2. The main bearing cap bolts must be tightened in the proper sequence. First the inner main cap bolts, secondly the windage tray bolts, lastly the main cap tie (horizontal) bolts.
3. Install the inside main bearing cap bolts and tighten to 20 Nm + 1/4 turn (15 ft. lbs. + 1/4 turn).

HOW TO DETERMINE CRANKSHAFT MAIN BEARING CLASS





This example shows how to determine the bearing class needed for each crankshaft main journal, assuming that a new crankshaft is being installed in a new or existing engine block. If the code 'B' 'B' 'A' 'C' is stamped on the #9 counterweight of the crankshaft (3), and the code '1' '2' '2' '3' is stamped on the side of the engine block (1), then main #1 would require Class 4 bearings, main #2 would require Class 3 bearings, main #3 would require Class 2 bearings, and main #4 would require Class 3 bearings.