I notice the other day when I was refueling my 1755 diesel the crank pulley was moving out of round. I felt it was loose so I tighted it up but it still moving (heavy 1/8 inch) so I believe it is the harmonic balancer. I need to look in my book to see what the correct torque is for the balancer. The question is it probably wore in the balancer or the crank. Hope it is not to bad were ready to plant winter wheat. Thanks.