If the vehicle in question shares the same transfer case as I, it would be a downgrade. My transfer case is the same used in the Range Rover and is chain driven (analog). Bulletproof!

So my understanding is, replacing my diff’s with a 3.64 ratio decreases my acceleration by 11%?

I agree on the TC, simpler is better. Understanding how the systems works and having owned/driven pre and post LCI X5's at the same time in snow, I just don't see any advantage to x-drive with non-locking front and rear differentials.

Your acceleration won't decrease by 11% by installing 3.64 diffs. Yes, in a given gear and at a given rpm, the accelleration at that point will be 11% less. BUT, you'll hold a gear longer (or downshift) and shift less on the way from 0-60. I bet your 0-60 wouldn't be affected if it required one less shift. Mine are in the process of going in; I'll let you know how it goes when I get her buttoned up.

Yes, please..

Well I did stated it manual swap it’s really not a big deal from what other people are saying I guess the differential is the way to go to swap....

What differentials are you using and where are you getting the gearing?
I’m definitely interested to see how it goes once you’re all buttoned up with it best of luck and can’t wait to hear the results.

I've got a set of front and rears off a 4.4L - they're 3.64 ratio. Fronts are a direct swap. On the rears, you have to pop out the stub axles from your stock 4.10 diff and move them over to the 3.64 donor diff. It takes all of 5 minutes, and you should be replacing the seals while you have it out anyway (which requires removing the stub axles).

I've got high hopes for the conversion because 1st gear is just crazy short, even for towing, and as you know, 5th is a screamer on the highway. With headers and EU2 tune, I believe I'm ~10% up on power, so the 11% taller final drive gearing should be, well, perfect!

PM me about the diff if the price is right..

Yes first gear and fifth gear is nothing in these cars with their manual.

I was just reading this

https://xoutpost.com/bmw-sav-forums/...ted-slips.html

The 3.64's are going on in my X5. Are you looking for a set of 3.64's or are you interested in my old 4.10's when I'm don with them? I don't have extra 3.64's. They're easy to find on ebay - just pick a donor with reasonable miles since normal people don't change their gear oil.

YES - that's the thread that originally gave me the inspiration to do this. I ran into a few inconsistencies when researching the swap, but I've cleared those up in the other thread I had about swapping diffs. Turns out it is plug and play on the pre-LCI cars (I was worried that the full rear axles would have to be swapped, but that's not the case).