XSeries-forum

Our nearly 9 year old X3 has not had an autobox oil change and none mentioned by BMW dealer. How often should it be done and should other oils in the 4wd transmission be changed at the same time? Is this within the competence of a general mechanic, or should I go to a main dealer or ZF transmission specialist?

I think the recommended interval is 60k but bmw says its lifetime oil ie the lifetime of the warranty 3 years

ZF recommend 8 years or 50,000 miles, whichever comes up first.

I would recommend getting the diffs and transfer box done at the same time.

I had a full driveline service done at less than 60,000 miles on the X6 and it made quite a difference. The transmission is much smoother now.

You do need to observe a temperature profile with the box or the levels might be incorrect. As long as you can read the transmission temp it’s pretty simple. Something like 50°C and cycle through all the gears in sequence whilst stationary, then check the levels again.

ZF do a proper kit with fluid, new pan/filter and new bolts (do not reuse old ones!l). It’s not cheap though. Correct fluid is a must (Lifeguard 8 for the 8 speed). Worth having a look underneath just in case there’s a support beam in the way of the transfer box fill plug (there is on the E70/71) so design may have followed for the X3 as well) that means dropping the support out of the way. Pan/filter is plastic and the bolts must be tightened in the right sequence or it will leak.

Certainly ‘diy’-able if you can get the car high enough. Any half decent Indy can do it, and there are videos on line showing how it’s done too.

Oh…..and

Thought the box on my old e53 was smooth when i got it on 164k but after a box service it was smoooooth.