My AC compressor failed and I had the X into my regular dealers service department (replacing under warranty, but waiting for it from Europe). I mentioned I noticed oil where I parked and asked them to take a look. They found the leaky actuator on their own and replaced it under my 100K factory extended warranty.

So how can one dealer say no it isn't covered and another replaced it - no questions asked?

Just guessing here, but either they thought it was covered and won't get reimbursed by BMW when they submit their claim, or they described the failure differently in order to get paid. That strategy only works until they get caught.

I just had this same problem.
 

I have a 2005 X5 4.4i which just turned over 120k. Last week I had the 4x4 light come on followed by the Brake and ABS. I noticed that when I switched the vehicle off, I heard a distinct knocking sound coming from under the car for a few seconds, like the sound of a stripped gear.

So, I took the transfer case actuator off the vehicle, partially disassembled it to the point of pulling the worm gear out, and noticed that "the gear" was indeed stripped, just like discussed above. I also noticed that it was only stripped on about half of the teeth, all on one side. The other half of the gear looked like it had never been touched. I'm not certain, but it appears to me that the actuator only utilizes half of the gear or only 180 degrees.

I turned the stripped gear 180 degrees and reinstalled it on the transfer case. Only time will tell if this will last me another 120k, but it did fix the 4x4, Brake and ABS lights. No codes, no warnings and it didn't cost me a dime.

I'll let you all know if this holds up, but so far, so good.

I did the same, it lasted about two months, when you accelerate aggressively it slips, then after time strips again..

Hello all. I recently had a TF case malfunction. I changed the actuator and it solved the problem. ( Thanks to a lot of help from Martin-C and this thread).Upon inspection I noticed the same wear pattern on the plastic gear. Now, I understand (somewhat) that this gear is responsible for engaging the multi-plate clutch assembly in the TFC. When it slips or becomes worn, the clutches no longer have sufficient axial force to transfer the torque from input to output. When I switched off/on, the code cleared. When I started it remained off. If I start, don't move, and then switch off, I hear a ticking noise coming from the actuator. When I pulled off I felt the car slip maybe once or twice followed by the trouble code (after which there was no slipping or lurching). This slipping may be caused by the actuator not pushing the clutches together sufficently.
Moving along in diagnosis without GT1 etc, I unplugged the actuator harness and there was no slipping at all as all the power goes straight to the rear without the TFC engaging. Bit the bullet and bought the actuator. It worked. Hope this helps fellow users.

ToddL, I just fix the actuator on my 2006 X5 with 85362 miles using the same technique as you did, can you please tell me if your still works good and how many miles since you fix it.

Thank you

Gabriel, it has only been a few weeks, but no problems so far. I had a comment from another member that said he tried this fix and it only lasted him a couple of months. I'll run it as long as it lasts, but if it strips again I guess i'll be buying a new unit. Good luck with it.

Thank you ToddL, I drove mine today is working fine. I check on the junkyards but they want to much money for an used one ($485-560), for that I will buy it new, ECS Tanning $720.00, one aging thank you and every one that post in this thread.

Is there anyone that can make that gear out of brass so that we poor souls don't have to drop a fortune on an otherwise fine unit.