Crankshaft Main Bearing: Description and Operation

This is a structural casting bolted to the bottom of the cylinder block to retain the crankshaft and to further improve overall rigidity.

Main-bearing clearances changes due to expansion are minimized by means of iron inserts cast into the main bearing cap main bearing supports.

Two hollow dowels align the main bearing cap with the cylinder block and the joint is sealed by beads of sealant.

The engine speed sensor is located at the rear of the main bearing cap and is a variable-reluctance sensor that provides an input of engine crankshaft speed and position.