Auto Transmission Fluid Type

Just purchased a 06 X3 with 66K miles and would like to change the fluid. From what I understand I need to change the filter, drain the fluid and replace, run for about 100 miles, drain and replace. Does this sound like a feasible idea?
Regarding the type or brand of fluid. The plate on the trans says to use BMW 83220024359, which I think is no longer available. Can I use Dexron IV. If I go the BMW they will want me to mortage my house and cat to pay for their fluid.

66K is early, can I ask what your reasons are? It can get costly and time consuming. Personally I'd got closer to 100K.

so can0n4 you suggest 100K miles to change the fluid? I am planing to do mine on 50k, since I feel the gear shift is not smooth.

For >2007 models, the manual says every 100K Miles (160.000KM)

For up to 2006 they say lifetime LOOOOOOL

Just do it every HALF of the max suggeted, in your case, I would do one now, it doesnt cost that much and yes, you can use Dextron III.

I agree with both responses fr Toronto. Please clarify that the procedure I outlined is correct.
Thanks,

I guess we should change our oil at half then too.....

2004 BMW X3, transmission says its lifetime right on it. I've already changed it twice, once at 100K, then again at 120K. It was shifting good at 100K. I could feel a slight difference after the fluid change.

Use LiquiMoly TopTec 1200 if you can find it. Don't get mixed up in the hype of all of the types, unless you don't care. BavarianAuto sells it in 5 quart and 1 quart containers. You could use Dex III or IV, but I wouldn't.

Drain the fluid, pull the pan, change the filter, fill it, start it, shift it all over, shut it off, then try and top it off if you can. Good luck.

"Lifetime" fluid simply means it'll last the lifetime of the transmission, which won't last much longer than 100k miles if you don't change the fluid. Automatic transmission fluids should be changed every 50-60k miles... it is a fluid: it wears out, breaks down, and gets dirty.

FYI: I just had the BMW dealer change my AT Fluid; they used a pump off the cooler lines to pump out the old and in the new. They charged $185. Well worth it considering the aggravation of an ATF change.

I changed mine a few weeks ago. I used auto parts store dex VI since I can't get the BMW fluid and that's what the transmission calls for if it was not installed in a BMW. Put 4000 miles on it since without a single issue.