who is 2004 that is stating that? Where? What article? Give us some light so we can learn from it.

Do you think they changed their mind or did they change the transmission? 2004 was the facelift. IIRC the X5 got a 6 speed. If they had changed their mind they would have published a revised service schedule. They didn't do so.

GM uses the exact same transmission as the early E53's that supposedly have lifetime fluid. GM suggests changing the tranny fluid (with DexIII) every 50k miles under the following conditions:

If the manufacturer of the transmission suggests 50k mile fluid changes under moderately heavy use, I think I trust that more than I trust BMW's "lifetime no matter what" approach.

I see your logic.

However, the criteria listed by GM for extreme service are related to both heat, and clutch pack wear. It is a matter of the safety factors design in to the system. The transmission fluid heat will be impacted by the trans cooler sizing and capacity. The clutch wear is directly impacted by the shift logic, and the firmness programmed into the transmission control module. It is also impacted by the BMW electronics that back off on engine power when the shift is executed, thereby reducing shock to the clutch packs. My point is that all of the above are different than the GM application. I don't think that GM knows more about BMWs than BMW, and I think that the BMW lifetime fluid recommendation is a joint engineering decision based on a multitude of factors. But I could be completely wrong, and the guys who printed the manuals could have decided it without talking to the engineers.

I agree with JCL. The demands and environment (heat, lack of combustion by products, etc) is much less in the transmission and differentials.

I just changed the diff fluid on our 98 323 after 193,000kms (120,000 miles) and it was still very clean.

I think fluids and tolerances are getting better and better. If you are not hard on your equipment I don't think you need to worry. Just be sure you are not running in the 'extreme service' categories.

having said all that, it is cheap peace of mind if you intend to keep the vehicle for a long time.

When BMW say "lifetime" they mean that should you have a transmission failure (i.e. WHEN) the cost of replacement will kill YOU!:rofl: :rofl: :rofl:

I'd definitely drop the pan and change the filter as well, it's pretty easy just a little messy.

I drained and filled my first tranny fluid at 50k as soon as warranty expired lol, then drained and filled at 75k during a stupid tranny gasket change, then i dropped the pan and changed the filter at 87k.
Needless to say filter was black as black can be, magnets were black, lots of sediment, no big pieces or anything but seeing the color and the fine "dust" like substance i'm glad i changed it. you just can't compare the new filter and new oil with old, it was a huge difference in how it looked.

no such thing as lifetime, this has been discussed numerous times, it's all a marketing gimmick... i could write about that for days, i've already done my research many times, before i actually did any work on my car.
if i believed in lifetime i wouldn't have touched it as early and often as i did ;)

I changed the filter and transmission fluid at about 85K. Other posts and photos convinced me, as I found the bottom of the pan and magnets covered with about 1/8 inch of sediment. There are some great DIY posts for the filter change.

I called my only two BMW dealers in my state today and asked for the transmission oil. One gave me price about $140 for 7 pints and the other told me I have to know the type that indicate on the oil pan because there are two different oils either Texaco 7445 or Dextro III. Is this typical? I thought they can tell by my VIN number. Is that easy to buy transmission oil from auto stores such as Autozone, Checker, or Pepboy etc. if I know what type of oil do I need? I am thinking about doing transmission oil and filter change in my 01 X5 3.0 85000 miles

ALX5

if it's a 2001, you more than likely have the ZF transmission with
ESSO ATF LT 71141 or VW G-052-162-A2
then you can just buy it locally at your favorite VW dealer for about $18 a bottle, or order online from bavauto for about $15 a bottle