Yesterday when I picked it up, everyone was in a bit of a hurry so I didn't really chat with them. Just got off the phone with them and have a better understanding of what their train of thought is.

They think that the clutch packs were gunked up enough after 111K of work that they were not functioning properly. They think changing out the fluid has helped immensely, and want me to monitor it closely over the next month or so, then perhaps change out the fluid again as more gunk works itself loose in there.

From a non-mechanic point of view, it makes sense to me. My only question would be, where did the gunk come from in a closed system?

Welp. It was good while it lasted. 😕

OMG.. That is the very first time I have ever seen LeMans blue trim on a car where I liked it. Holy sh!t. That red.. that black.. that blue..

Totally hawt.

Funny. The blue is the single thing I'm not completely sold on.

That and the shake.

Well, the shop is researching options today on rebuilt vs. new transfer cases. Any thoughts? From my basic googling, it seems a lot of the remanufactured parts are as much if not more than new.

Best price I found was a reman from TomkinsonBMWparts.com ... any feedback on this vendor?

Any other last minute suggestions? (I say 'last minute' like I can afford to buy a new transfer case today. It will be a bit before I give the go-ahead.)

www.cobratransmission.com - Sells every part for the ATC500 and remanufactured cases as well.

I still think the shop you have it at has no clue what the problem is and are only recommending replacement because they just want to get it off their lift, and don't want to take time to take the case out and diagnose properly.

Cobra sells a Remanufactured ATC500 for $2,223. If you take that 4k number from BMW you're joking yourself.


Find a driveline/transfer case/BMW specialist in the area if you can, unless you really have faith in this shop. I'm guessing your options are limited in your area.

It's not on their lift. I've taken it home each night it's been in there, so I don't think that's the problem. I talked to the mech who actually did the work on it yesterday and he said he could literally see the transfer case 'jumping' when it was on the lift and they had it shaking.

I'll look at Cobra, but the Tomkinson price was $1922 for a reman.

When I said "$4K" I was rounding. I haven't been given an actual quote, that just came out of a quick conversation with the shop when he was just rattling things off...adding in his head. I think he actually said something more to the effect of "Well the part is probably $2700, add the labor and another $50 for the oil and you could be pushing $4000." That was never an official estimate, that was him guessing off the top of his head. He hadn't priced anything out yet. With a decent price on a reman, I think we can probably get it done for $3K or less.

So, I guess I do trust the shop. They've never been anything but honest with me and helpful. They admit they can't guarantee this will solve the problem, but they do believe the part is bad.

The fact that they had it shaking while on the lift does tell me it's not a sticking caliper, it's not a CV joint, and it's not a suspension problem, right? Wouldn't those all require ground pressure to manifest themselves? They did inspect the calipers and they are all working fine, so brakes are definitely ruled out.

I'm definitely open to suggestions if anyone has a better thought. Trust me, I'm not a mechanic, but I've spent a ton of time thinking about this and learning how this thing works and trying to figure out what the problems are, but quite frankly, the best lead I have right now is the fact that they got it to shake on the lift and were able see/feel the transfer case shaking, and when they put their scope up to it they could definitely hear a rattle inside it.

Thats so weird man, have you flipped the actuator gear at all? The shop sounds like decent guys now that you mention in detail, so thats good.

The problem is that it may be a $150 bearing or output shaft or something that is bad, but the rest of the case is fine. That's what I have trouble with, I'd at least have them crack the case open (which shouldn't take more than 2 hours) and see what is going on internally. If they find a broken part, good, replace it, and put it back together and you're on your way. If they don't, and still think its the case then order a reman one then.

Have you also checked the motor mounts?

The motor mounts haven't been checked, as it doesn't shake at idle, or startup, or anything really, just once it's warmed up and at speed. It's something I can possibly have them look at today.

I'll inquire about opening up the case and diagnosing. The other thing I had considered was swapping out the case and eating the core deposit, then having someone rebuild this and then sell it to recover some of the cost of the replacement...

Regarding the actuator, that's something I asked about when he first mentioned the transfer case. I brought up flipping the gear, he said if he was going to take it apart to flip the gear, he'd order the carbon fiber gear for $100 and just replace it instead of flipping it, but that the problem didn't seem to be coming from the actuator motor, so it was a moot point.