Bobcat S76 Grinding Noise from Left Chain Case
Fault Codes & Symptoms
Loud grinding or rumbling noise from the left side chain case, most noticeable when turning. Related symptoms: - Machine pulling to one side - Excessive free play in one wheel - Metallic debris in chain case oil Operator reports a loud grinding noise from the left side of the machine. The noise is constant while driving but gets louder when turning right (loading the left side).
Confirmed cause: Failure of the front axle bearing assembly. Repair performed: Drained and flushed the chain case to remove all debris. Replaced the failed front axle bearing and seal assembly. Replaced the damaged front axle drive sprocket. Replaced the broken forward drive chain. Re-assembled the chain case with new gaskets and filled with the correct fluid. Verification: Operated the machine in forward, reverse, and performed tight turns in both directions. The grinding noise was eliminated. Re-checked chain case for leaks. Technician notes: - The initial failure was the axle bearing, not the chain or sprocket. - Failure to thoroughly flush the chain case after a failure like this will lead to repeat failure of the new components. - Carefully inspect all sprockets after a chain failure, even if they look okay from a distance. The drive motor and idler sprockets were not damaged in this case but could have been.