06 X5 4.8is.. First off, I have searched and searched and cannot find anything that seems to appropriately discribe my symptoms. X has 98k miles on it, originally I bought it cpo from dealer with 62k on it. Had trans fail, replaced under cpo, valve seal leaks, repair cpo. Right around time of trans replacement I put new continental dws's on. So get x back and I start to feel slight shudder/hesitation is the best way to describe it. I'm not an idiot I know the difference between a slip, miss, fuel problem symptom. It's not that, this is best described as a hesitation or a shudder. No loud noises, shake or anything. So anyway, to make a long story short, dealership could not feel or reproduce, blab, blah, blah.. Dealerships suck.. Car goes out of cpo. Probably best thing that happened, no longer going to dealership. Still condition got a little more frequent and pronounced. Took to local bmw shop, good no question, used them before on my vw, Porsche and previously owned BMW's. So what has been done so far... Only light that was on was 4x4, previously diagnosed as bad steering angle sensor. Light would come on and off and you could still communicate with sensor, recalculate, etc. but it wouldn't hold anymore. Let's start there.. Put one on. Drive vehicle no change in drive performance but light stays off. No the problem but fixed that. So then go to tires. Get all rebalanced although I was pretty sure that wasn't it had already had done three times since problem started and got new tires. Didn't fix. Well, have heard sometimes tires can actually mess with the drive system and cause it to malfunction. Let's wait till he gets another x in and swap wheels and see what happens. Takes forever for another e53 series 4.8is with the correct wheels and sizes to swap. I appreciate effort out of my shop to eliminate that, but that's not it either. No change. Unplug actuator motor, problem goes away, I new this had tried before. So pull actuator motor to check gear. Took apart, no more warn than a part should be at 98k. Defiantly was no actuator gear problem. So here I am. Drop money on new actuator motor, or just concede to the replacement on transfer case. I have not seen anyone replace an actuator. The gear seems to go bad but that's it. Has anyone ever heard of this problem and a resolution? X has same xdrive transfer case as facelift x5 e53 and I believe the first x3's also, probably more. Transfer case is the atc500. So whatcha got for me guys?