Assuming one could work out the electronics, I just wonder if it would not be easier to fit some sort of American transmission. Use an adapter plate between tranny and engine, (done all the time). Getting the tranny shaft splines to mate with the motor would be the only challenge. (I'd bet Advanced Adapters could make this! Probably means a custom or machined shaft for the tranny.) From there, it would all be easy mechanically. There are plenty of tailshaft adaptations available currently for HD manual transmissions that will allow bolting up to a TC. Bolt on a 249 TC from a FT 4WD Jeep or something similar,(bonus would be a low range). Mating it to the BMW driveshafts would be easy; ~$350 for each shaft or less. Just send both BMW shafts to Tom Woods, give him the measurements, and tell him what TC you are using. Done. Custom tranny/TC support, (again pretty easy).

No complicated castings. Stonger tranny. Stronger TC...with Low Range. Are not some of the BMW automatics sourced from GM? Maybe the spline mate up would not even require a custom tranny shaft to use a Corvette or other GM tranny???? Just an adapter plate. I'm pretty sure a Corvette 6 speed could be converted to 4WD with off the shelf parts.

If you are serious about doing this in the US...why not give Advance Adapters a call? They make all sorts of crazy drivetrain swaps possible.

Yes, and I forgot to mention, the whole shifting mechanism was custom made too. So I have a short-shifter.

I was thinking about installing the MB G500 TC and also other options, but my goal was to change as few parts as possible. And so, only 4 custom parts were made for this conversion.

The bodywork wasn't touched at all, nothing was moved from stock mountings.

The car drives and feels just as it came from factory and feels great at high speeds, drivetrain doesn't make any sounds and so on....

Using a different TC would mean I had to cut and weld the bodywork, without any idea, how it will work at the end - so that would only produce more sources for possible imperfections.

But still, it's an option - some one can try this way out.

Here's the screenshot of the offer I received from one german foundry.

As far as the TC's I was talking about, the AWD cases I was referring to are basically about the same size and shape as the BMW case, (logcal, since they all come from the same factory!) The tailshaft of the tranny with determine the "clocking" but that's not difficult to change. I don't think that would be an issue at all.

That price quote above is exactly why I suggested this...that's crazy expensive if I'm reading this right.

TC swaps are VERY common in the 4WD world here in the US. As a matter of fact I did one in my Jeep; ditching an AWD case for a 4WD case more robust that never came in that vehicle. I used a custom front shaft that replaced the CV joint with a robust U-Joint, (a real WEAK spot), and shortened the rear shaft. Not too expensive or difficult at all. Counting both shafts, a used TC from eBay, full rebuild parts for the TC, all told I spent about $800.

Wow, those prices are insane. I am going to say that is some expensive casting.

You know what we need to do. Is get RRPhil to take a look at his Transmissions, and let us know which BMW manual trans can accept the TC, and which trans can be rebuilt using the transmission output shaft from the auto.

I think you'd be better off carrying a BMW V8 crankshaft into a transmission shop, and seeing what fit in that.

True.

Check out this web page:

If anyone can make the right parts, I'd bet this place could:

Engine to Transmission Adapters | Advance Adapters

Once you have a T-5 or whatever bolted up to the engine, all the other mechanicals will be easy; everything would be off the shelf except driveshafts, which can be ordered inexpensively. These are trannies that can be built to take huge power, (worked LS1,3,9, etc), so that will not be an issue.

Then it's just the electronics, and that would seem quite difficult to me.

How can you find a different TC for some other tranny, keepeing the mountings in the same position? That will need some bodywork changes for sure!

The NV125 is very compact and light, thats one of the smallest TCs on the market, you hardly can find anything, which will fit into the tranny tunnel - it was even not an easy task to fit the adapter housing I used....

And as I allready said - you'll add some heavy offroad TC to a car which is supposed to go 160+ mph (which I'll do on autobahn). X5 isn't a jeep ot land cruiser, so if looking for different TC, so than one from Cayenne or at least from a never vehicle.

In that case I would rather buy a different chassis and put the X5 body on it...

The offer I'm stated was from german company, while I did it in Russia for much much less money. I was totally involved and that saved me a lot of money.

You can fit any transmission to the engine, just by milling the adapter for the bellhousing, or you can weld a suitable bell housing on T56 tranny or any other - one the only thing is to make a bulge for the starter and use the right flywheel.

The adapter kits, offered by the company you mentioned are ready kits, which were produced in some significant numbers, while mine is only one for now. Assuming, there will be like at least 10 orders for the adapter kit like mine the preice will shrink drastically.

So the request would be "how much would a development for the X5 tranny swap kit cost?"

Still I'm very interested in that - so who will contact them first?

? What do you mean? 540i flywheel will fit on that, but it has nothing to do with the bellhousing....

The easiest way is actually to get the manual tranny from the 3.0 X5 and blot on the housing from the 6-speed tranny from 545i on that. In case of 5 speed tranny from 3.0 pre-facelift and M5/540i tranny the bellhousings are even interchangeable, the thing is the bearings of the main shaft on 5-speed tranny are weak. You also have to use the flywheel and clutch from 545/550i or 6-series.

First of all, you have to find a guy, who can promise you, he will adapt the x-drive logic to the manual tranny and V8 - that's what I'd do first.