I had just over 100k miles. The vehicle is a 2001 x5 3.0 that I 've owned for almost 8 years.

There were no warning signs. I was at a stop light. I attempted to go and a grinding sound came from under the car. The car would not move. I had it towed to the dealer who gave me the estimate indicating that it was the transfer case and the front drive shaft that needed to be replaced. He wanted to get only new parts, 2500 for the transfer case and 900 for the front drive shaft and then labor totaling 4300. For a car with 100k miles, I said no way and I towed it to a local shop (non-BMW) who dealt with transmissions and he said it wouldn't be hard to fix. I got the transfercase on line a transfercases.com I believe for about 1k and then the shop called some junk yards and found a good condition front drive shaft from a junked x5 for $300. Actually, I googled the part and there are cheaper ones available on line (about $250 or so).

I would have done the repair myself and I'm not a mechanic but I don't have access to a lift so I though it would be a little too challenging so for $400, the mechanic did the labor in a morning. I now have about 104k on it and no problems. I am in NY and the junk yards seem to be around NY where they found the used front drive shaft but I don't know which yard. Also, I tried to locate an aftermarket part and nobody seems to make a replacement front drive shaft.