2005 X3 3.0 Transfer case clunk
 

hello all, new to the forum and had a question to throw out for anyone with an idea about it. my x3 3.0 AT has 155,000 miles and recently i did an oil pan gasket ( not worth the time but at least its clean underneath now). when pulling the front driveshaft the yoke and shaft came loose from the transfer case and leaked some of the TC fluid out (maybe 200-400 mL). didn't think anything of it and once everything was back together i got some of the super special "BMW power box oil" @ $70 a quart. topped the TC fluid off and went on my way.

now im getting a clunk and slight hesitation in 1st and 2nd gear that feels like its coming from the TC . going to try changing the fluid completely and resetting the computer for it (because apparently its smart enough to know its not happy but not smart enough to know why). im curious as to whether anyone has encountered this issue. ive read plenty about different transfer case issues from squealing to humming and everything in between but it seems as though my issue is somewhat unique. im almost certain its the TC but believe there's a snowball's chance in hell it could be the front CV's. any help would be greatly appreciated.

I've just had a similar problem. I had a clanging clunk when ever changing from Drive to Reverse. I discovered I had a worn spline on the front drive shaft which I've greased to quieten it down while I figure out what to do next. I appears to be quite common.
I was looking for posts on this topic when I found yours.

My wife has a 2009 330xd and we had a clunking going on when the car is under a heavy load "full Gas" and I told them I think it was the TC, they hemmed and hawed and tried all kinds of other stuff but in the end it was the TC, try driving up a steep grade and give it full gas in 2nd or 3rd gear, if you feel it clunking it's your TC...