Which of the following would cause the dowel or locking lip of a split-type, precision insert, main bearing to shear and allow the bearing to rotate with the journal?

Correct Answer: Option C — Insufficient bearing crush

Insufficient bearing crush fails to provide the radial pre-load required to firmly seat precision insert halves against the housing bore. Without adequate interference fit, frictional drag from the rotating journal easily shears the locking lips, allowing the bearing shell to spin.