how does a motor spin a crank bearing

 

Usually lack of or poor lubrication will allow the bearing to adhere to the crank journal surface. As the crankshaft rotates the bearing that is now stuck to the crank will rotate within the rod bearing surface. Another cause is a slight hydrolock that bends the rod enough to put excessive pressure on the rod forcing the bearing to crank journal clearance to close and eliminate room for oil and the same thing happens. Debris can enter the clearance area via the crank oil feed hole causing loss of oil heat and clearance issues as well. To much bearing to crank clearance caused by wear will allow the pounding effect to hammer the bearing flat just like a blacksmith forging a horseshoe and the bearing will spin.

 

how many miles?

 

104k