Over 150k miles on trans in my '03 4.4 Spt Pkg, 3 drains/fills (1 week of driving between each drain fill to minimize "new fluid shock") and new filter at 100k miles. I have thousands of miles towing a 6k lb trailer on the X too.

rather encouraging poast @150k, if I can get mine to go that far I'll be good.

BTW, are you on original xfer case?

The best assurance I can give you is this: If you like your X and plan on
keeping it, figure on setting aside about $4000.00 to replace your transmission
when the time comes. Now compare that to paying for a new X and you should
be feeling real good right about now.

I wouldn't change it. But I would put some money aside to pay for a new transmission (or a rebuild) when it eventually fails. I just don't believe that the fluid change extends the life, so it is throwing money down the drain.

If you do change it, make sure you use OE fluid, not a generic fluid that fits everything. Also use an OE filter, not an ebay special.

The dealer doesn't turn down the transmission fluid change job because he wants to sell a transmission at some future point. If he doesn't do it, you will just get it done elsewhere. He turns it down because he doesn't want you claiming a new transmission off him on service warranty if the transmission fails soon after the fluid change, and he has seen it enough times to have decided that it is better to forego the revenue from the potential fluid change than to risk it. He is actually putting his principles ahead of potential revenue. He could just take your money and get you to sign a disclaimer that any subsequent failure is on you, not him.

^^^^^^ exactly what dealer said..save the $$$ for a new tranny.....

thanks!!...i actually might just create a seperate account just for the transmission and stop worrying every time I go to give the X some gas

It's been overly discussed, but I say change it. No oil lasts forever.

As I stated in post #11, changed OE fluid at 100k miles and now at over 150k miles including ks of miles subjecting the trans to 12k lbs of truck/trailer weight to pull around. These +50k miles have been on Castrol UltraSyn Multi Import ATF that meets the LT 71141 spec. If non-OE fluid+100K miles B4 fluid change=trans failure, I would certainly have not be able to reach 150k miles on my the trans in my X.

IMHO, Me thinks that some who've had a trans fail after switching to a non-OE ATF had some other trans issues that caused the failure.

100% agree. My indies, 3 owners, and a ton of shops, had 1 trans failure after oil change in the entire time of running shops. They said they knew that trans was going to die anyway. When they changed the fluid, car would not move at all. They put old fluid back in, and it drove to the trans shop.

They say that BMW lifetime fluid bullshit is bullshit. Same as start the car and drive right away. Remember, BMW has to make the car last to 100K. After that its profits for them again when you show up with whatever is busted.

So don't change $80 worth of oil, and save up $4k worth of transmission. Yea, that logic is brilliant. Or maybe $80 worth of oil, with get you to 150k miles, instead of the usual 100K. Think about it guys.

The only BMW fluid in my truck is the coolant. At 100k miles Redline ATF went in the powersteering and transfer case, Mobil [1] 0-40 Syn in the engine, Ate SuperBlue Racing brake flush, Mobil [1] Syn 75-90 in the diffs, 10 ozs of Lucas upper cyl lube in every fuel fill, except for 2 fills each year (spring and fall) with Lucas Ethanol Fuel Conditioner/ Water Remover. X has no leaks ANYWHERE and NO gaskets or seals have been replaced. When cold started, X is allowed 30 secs of warm up B4 driving and NO WOT until coolant temt gauge has reached full temp. Truck is also give 30 sec cool down with ALL accessories off when pulled into the garage at night. When it sits for over 3 days, a charger is connected @ 8 amps and X is started after battery show 100%, If X is left for over a week the charger is connected in float mode. This is done on ALL my vehicles, never had any electrical issues other then a FSR and burned out turn signal bulb.