BMW X5 Jerking: Transfer Case or Transmission Issue?

Hey there! I have some experience working on cars and went through something very similar with my '02 BMW X3 3.0i last year (I also own an older 5-series). The symptoms you're describing sound exactly like what I experienced, jerking, rough shifts, and AWD issues. Turned out the transfer case had worn-out gears causing all these problems. Initially thought it was just low fluid too, but my mechanic found the actual culprit after a thorough inspection. The repair involved replacing the defective gears in the transfer case. Cost me about 330 Euro at my trusted workshop. Since then, the car's been running smooth with no issues. Could you share more details about the error codes you're getting? That would help confirm if we're dealing with the same problem here.

Thanks for sharing your experience! Currently at 160037 KM and just had my service last month. I'm getting the same symptoms you described with your X3. My mechanic initially suggested a transmission fluid change, but after reading your post, I'll have him check the transfer case gears too. Just curious, after your repair, did you notice any immediate improvement in the shifting and AWD performance? Those gears definitely sound like they could be the root cause of my problems too.

Hey again! Glad my previous post helped point you in the right direction. Yes, I definitely noticed an immediate improvement after the transfer case gear replacement on my X3. The jerking completely stopped, and the transmission started shifting like butter again. The AWD system went back to working perfectly too, you can really feel the difference, especially during acceleration. Since you mentioned your mileage (mine was around 155000 KM when I had the issue), it's right in that range where these problems typically show up. The transmission fluid change your mechanic suggested isn't a bad idea, but in my case, it wouldn't have fixed the root cause, those worn transfer case gears. Quick tip from my experience: when they do the repair, have them check the surrounding seals too. Mine were a bit worn, and I had them replaced while they were in there. Saved me from potential future leaks. Let me know how it goes after you get it checked out. Really interested to hear if your X5 has the same issue mine did. These BMWs are great cars, but they do have their common weak points!

Really appreciate the detailed follow-up! That's super helpful info about the seals, I'll definitely mention that to my mechanic when I take it in next week. Your experience makes total sense, especially since our cars have similar mileage. I was getting worried about potentially needing a whole new transmission, so this is actually a relief. The fact that you got such immediate results after the repair is really encouraging. I've been babying the car lately, trying not to push it too hard with these symptoms, but it'll be great to have it back to normal. Will definitely have them do a thorough check of those transfer case gears and surrounding seals. Think I'll go ahead and book it in tomorrow, no point waiting around with these symptoms getting worse. Thanks again for sharing your repair experience, it's exactly the kind of real-world feedback I was hoping for. I'll try to post an update once I get it sorted out!