Does anyone know if changing the trans control unit will required a fluid change?

Only if the version of the control unit is updated and it requires valve body change. Then you'll need to pop the pan and might as well change the fluid.

Gilly

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I was going to try to change the AT fluid and filter myself. However, I was told that 1/2 of the old fluid will remain in the torque converter unless I drain it too. How should I handle this? Is it difficult to drain fluid from torque converter. Or, should I change the fluid a few times to get it clean? What do the service techs at the shops do? Thanks for any advice!

By the way, I've got 99 ML320 with 95k miles and fluid hasn't been changed. This will be the first if I can find out how to do it.

Very easy to drain, at least on my 1999 ML 320. There is an allen head bolt that you remove from the torque converter, it's small maybe 5 or 6mm. You just turn crankshaft from front with I think it was a 27 or 32 mm socket until you see the allen bolt.

Regarding the torque converter draining, try this link, it is a posting of an article in the Star Magazine with clear directions and pictures on draining the trans fluid:

http://www.benzworld.org/forums/forums/thread-view.asp?tid=1182558&posts=7&hl=

The picture is upside down but the information is clear enough.

You will be too when you're doing this job. I agree with Ron, quite easy. Your '99 has a drain plug in the torque converter, but the newer ones don't; it was discontinued at some point.

On my '98 you turn the crank with a 17mm hex driver.

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'10 GL550/'04 BMW 545/'99 BMW 323/'98 ML320/'87 VW GTI (race)

Thank you all! Very helpful. Will try it this weekend.

I bought all of the stuff to change the tranny fluid and filter. Most of the information on this forum is accurate but a few things were left out and I have 2 questions.

Be sure to buy two of the seals for the cooling hoses as you will probably need to loosen or remove the one on the driver side attached to the bell housing. Be sure to get both old seals off the banjo bolt to avoid a leak.

On the passenger side there is a cover over the electrical connection to the tranny and you should remove it before undoing the tranny pan bolts.

Two questions:

What is the torque for the pan bolts?

My dipstick would not go down the all the way. It seems to bottom out with about a foot to go. The reading seems just fine however. Is this normal?

Thanks.

What is the torque for the pan bolts?
8NM

My dipstick would not go down the all the way. It seems to bottom out with about a foot to go. The reading seems just fine however. Is this normal?
If it's the one for testing the level I don't recall it going all the way down either.

That's correct.
8nm on the pan,
And the dipstick does not go all the way down. I think it was produced that long because the 140's have a really long dipstick tube, and that dipstick is made to check 722.6 tranny's on any benz.

Just to update the 722.6 transmission file, MB now subs all parts directly related to the planetaries to a full planetary assembly, taking all the options out of rebuilding. After you pay more than $2K for that part/assembly alone, then a few other necessary updated parts, you may as well just buy the transmission from Benz; there's too many other parts that can go bad in that transmission to justify saving a few 100 dollars on an aftermarket rebuild. Be careful with used parts; remember, you're replacing fatigued and failed parts with known defective parts, and you're just looking for trouble unless you just want to unload your vehicle. This absolutely sucks, as this was a most enjoyable transmission for me to rebuild.

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