Mounting Damage & Incorrect Fit
Damage from incorrect fitting practice, wrong clearance, or poor shaft/housing tolerance.
Symptoms
Score marks on bore or outside diameter from hammering or pressing, cracked rings from excessive interference fit, cage damage from mounting force applied to the wrong ring, or loose fit causing creep and fretting on the seat.
Likely causes
Incorrect mounting method (hammering, pressing on the wrong ring), excessive interference fit, undersized shaft or oversized housing bore, or lack of cleanliness during fitting. Loose fits allow the ring to creep on its seat.
Prevention
Follow the manufacturer's mounting instructions. Use induction heating or proper cold fitting tools. Apply force only to the ring being fitted. Verify shaft and housing tolerances. Keep everything clean. Use the correct internal clearance class for the fit.