Looking to buy this vehicle. 61,000 miles. Drives,steers and turns normally except when you do a very tight 360 circle. Tremendous grinding sound and shuddering coming from the rear of the vehicle. Return to driving a straight line and everything returns to normal. What is the issue and what would it cost to repair?
It sounds like a problem inside the AWD differential. It could need a whole new AWD differential.
It’s possible it just needs the differential fluid replaced. But you’re taking a chance, and worst case is that it needs a new $2000 differential because the previous owner failed to change the fluid as recommended, or the fluid leaked out and damaged the differential.
So the short answer is, the cost to fix is anywhere from $100 for a fluid change to $2000 for a new differential. And “tremendous grinding” makes me suspect the latter.
I suppose you could suggest to the buyer that he change the diff fluid on his own dime, then do another test drive and see if the noise is gone. But there could still be permanent damage done to the differential from the dirty/missing differential fluid that it probably has been run with.
I would walk away.