The OEM manual says the Transmission...

[E53inLA]

Originally Posted by Ghost-Flame

My original post was intended to bring light to the fact that the maintenance specification Says, you MUST change the fluid at 100K miles. Yeah you can choose not to, I suppose , just like you can choose not to change your oil or coolant.

I did not mean to get into a pee-ing match over a discussion over the minute, semantic argument regarding spec, license, suggested, compatible choice of ATF.

Use whatever darn fluid that satisfies your desire as long as it is formulated to the dexron3 recipe.

+1

I change it every 30K or 3 years, so I'm almost due for a 2nd change at 57k miles now. Why so often? I think it['s fair to say 30K in stop & go LA traffic is equivalent to 100K "normal" driving patterns.

When the X5 was under BMW maintenance I asked at the dealer and the SA told me "never" change the ATF. So I then asked how much $ do they charge to do it. To my shock, he wouldn't even quote a price, just said they would not perform that service even at my request. Maybe because the X5 was still in the warranty period?

This first came up with my 1999 MB E320. At 90k miles I was having some very minor slipping, so I took to an indy transmission shop for a checkup. They drained the fluid, told me "it is shot", put the fluid back in and told me the solution was a $3,500 rebuild. Did some research and decided to change the ATF for 1/10th the cost. I was told that NEW ATF could either make the problem better or worse (if the clutch plates went bad faster), but would protect the gears better. E320 has been fine ever since.