Differential Bearing Failure
 

My 2009 XJ was towed off the highway after filling with smoke yesterday. Pinion bearing in front of the differential failed, and the oil was on the exhaust pipe. Only 50k on the car; is this common???

I would hope not. Haven't heard of that particular issue before, but there's always the first time of when, not if, it was going to happen.

I have a rear diff that leaks out of the shaft /diff mounting box and needs periodically refilling (that I actually got out and done today) but so far have not had any drip onto the exhausts.

Must be lucky I suppose.

Very unusual fault, and I have not seen a post on this previously, but like all parts on a car, the possibility is always there of failure.

Was this covered under warranty? I had to replace the differential on my previous Jag, an S-Type under warranty since it was a Select Edition car. You may also want to check out any TSBs that cover differentials.