BMW M2 Transfer Case Issues: Help with Jerking & AWD Errors

Hey there! I had a similar problem with my 2017 BMW M3 last year (I have some experience working on cars as a hobby). The symptoms you're describing sound exactly like what I went through, jerking, transmission warnings, and AWD acting weird. After struggling with it for a bit, I took it to my trusted workshop where they diagnosed defective gears in the transfer case. The fix wasn't cheap, set me back about 330 Euro, but it solved the problem completely. They had to partially disassemble the transfer case to replace the damaged components. Before we dive deeper into potential solutions, could you share: Any specific error codes you're getting? When exactly does the jerking occur (during acceleration, shifting, etc.)? Have you noticed any unusual noises? Current mileage on your M2? BTW, if you're considering keeping the car long-term, I'd definitely recommend getting this checked out ASAP. Transfer case issues tend to get worse and can damage other components if left untreated.

Thanks for sharing your experience! My M2 just hit 144064 KM and had its last service about 2 months ago. I'm getting a "4x4 system malfunction" warning on the dash. The jerking usually happens when I accelerate from a stop, and there's this weird grinding noise when turning at low speeds. I'll definitely take it to a mechanic this week based on what you're describing, don't want to risk more damage. Did you notice the grinding sound too before you got yours fixed?

Yeah those symptoms are spot on! I remember that grinding noise all too well, it was exactly the same in my M3, especially during low-speed turns. It's like a rough, metallic sound, right? That's typically a dead giveaway for transfer case issues. Looking back, I wish I'd acted sooner when I first heard that noise. The grinding sound in my case got progressively worse over about two weeks before I took it in. Your mileage (144064 KM) is pretty close to where mine was when it started acting up too. One thing I didn't mention in my first reply, before I got it fixed, I noticed the problem was way worse on cold mornings. Did you notice anything similar? The jerking during acceleration became really pronounced until the car warmed up properly. Since you're planning to take it to a mechanic this week, quick tip: make sure they do a full transfer case fluid analysis. In my case, they found metal shavings in the oil, which confirmed the internal gear damage. The earlier diagnosis helped prevent additional damage to the surrounding components. Let me know how it goes after your mechanic looks at it. I'm curious if it's the same issue I had with the gears. Mine's been running smooth as butter since the repair, no jerking or grinding at all.

Thanks so much for the detailed info! You're absolutely right about the cold morning thing, it's definitely worse before the car warms up. I'm glad you mentioned the fluid analysis too, I'll make sure to ask the mechanic about that specifically. The grinding is exactly as you described, that metallic sound is really concerning. Getting it checked first thing tomorrow morning actually, your experience has convinced me not to wait any longer. Really hoping it's just the gears like in your case and nothing more serious. I'll probably need to dip into my savings for this repair, but better than risking more damage to the car. Thanks again for all the help, it's super reassuring to know someone else went through the same thing and got it sorted out!