you are most welcome to the pics although i think other posters input is good , you should consider purchasing a manual from bentley if you are going to maintain x5 yourself .

I second that, the Bentley will be a great resource for you if you plan on keeping the car and want to learn more about it.

Another Question, BMW Claimed that our X drive system can independently allocate power to each wheel, if the x-drive only determine power to front and rear axle, does the differential does the left and right job? Or when you are in a turn, the axle automatically switches power?

There is info on x-drive on the homepage and so forth.

X-Drive allocates power front and rear. Side to side balance is achieved via the DSC system which applies a wheel brake on the wheel on the side that is spinning. The differential is open, ie not a limited slip design. When you are in a turn, the differential does the normal variation in rotation speed, but that doesn't switch power, it switches speed.

Thanks! The article on the front page kinda suggest that X-drive is allocating power individually to each wheel, which in reality, it's only going to front and rear.

So the theory that they suggest that 100% of power to 1 wheel is not really possible as if power is 100% to the front wheel, it's split between 2 wheels, and then dsc brake one wheel and left the other wheel turning. Well~ Thanks for the input guys!

x-drive rebuild?
 

Hi there Killcrap - is the x-drive unit servicable, that is can the clutch pack and chain be replaced?
If so, are the spares sold seperately by dealers.
lastly would you recommend a rebuild
many thanks

The parts are not available at the dealer, and properly rebuilding is more difficult than it would seem because it is measured to know what classification resistor is needed.

Here's the link to my Xdrive DIY that I posted a week or two ago:

http://www.xoutpost.com/bmw-sav-forums/x5-e53-forum/71037-xdrive-transfer-case-fluid-diy.html?highlight=xdrive+diy

You're going to need Xdrive fluid, which I found at ECS Tuning. And yes, the TIS does advise you should reset your adaptation values after changing the fluid. I haven't reset mine yet and I frankly am not terribly worried about it.

Bavauto sells this code reader that says it will do all of this:

BMW Parts and BMW Accessories | Bavarian Autosport

Fault code reader shows you what the problem is on an LCD color display. Launch Tech's CReader VI (pronounced "see reader six") reads and clears manufacturer specific BMW and MINI "check engine" fault codes as well as all standard OBD-II codes.

Features include: Choice of language, English, Spanish or French
Special tests for Evaporative system, Oxygen sensor, Inspection readiness, MIL( check engine light ) Status, VIN Info, and on-board monitors
Fault-code search function
Free internet updates
On-screen help function and more.

http://www.launchtechusa.com/assets/.../CreaderVI.pdf

Can you resist the transfer case with this?

I plan to buy one either way, it looks like a good tool to have.