Changing ATF? - PeachParts Mercedes-Benz Forum

Erwin Stapel · #1 10-27-2005, 02:29 PM

We own a '99 ML320. It has 110k. The transmission fluid has never bin changed. Is it time to do so? Should the filter be changed? I ask this because my mechanic told me he can flush the transmission without dropping the pan.

blueranger · #2 10-27-2005, 08:33 PM

ouch
i change mine every month and its not over kill either...

at 110 k miles i would not have the guy do the pump thing...

DCF · #3 10-27-2005, 09:20 PM

Every month? Why?

MB intended that the fluid never be changed, which is why the dipstick has that "lock" on it. While, I would not say that "no change" is not the best plan, and certianly after 110K a change is probably in order, there is no reason to ever change ATF in a car more often than once a year at the most (even in hilly terrain or with a trailer involved). The only reasons to change ATF are to keep it from sludging (which modern ATF really takes a long time to do) or to get rid of fluid contaminated with metal particles from wear on the gears/clutches/bands. If any car is wearing things so fast that changing the ATF every month results in noticable metal, then something is definetly wrong (and I doubt even possible as the Trans. would have died a long time ago).

I have to ask, if you change the ATF every month, how often are you changing the oil?

Ali Al-Chalabi · #4 10-27-2005, 11:02 PM

Do a search on 722.6 transmission fluid changes and you will find a ton of info.

If you do change the fluid, drop the pan to clean in out and also change the filter in the transmission. The pan has to be removed to change the filter. Make sure to only use the original MB fluid in that transmission as it is the only approved fluid. And also, in case you don't know, be aware that there is not dipstick in the transmission tube. You will need to get the shop tool dipstick and a new locking cap for the top of the dipstick tube.

blueranger · #5 10-28-2005, 12:23 AM

well dcf they tell you that you can change the oil
once ever 25k miles to... so do you believe that..

i have some swamp land i would love to sell you....

my transmission is at 247k and it is about to die.. so i am currently
changing it weekly.... trying to squeeze some more miles out of it..

i would not pay 100 dollars for a car with 110 k miles that had never
had a transmission fluid change....

mbdoc · #6 10-28-2005, 08:05 AM

Have the fluid changed in a normal fashion!

THAT & all 722.6 transmissions use SPECIAL synthetic fluid!

MAKE sure they all the special magnet MB # 220-271-00-98!

Ali Al-Chalabi · #7 10-28-2005, 01:52 PM

Blueranger, is that tranny you are changing the fluid in weekly a 722.6? The fluid for that thing is like $13/$15 per quart!

There are a wide range of opinions here on 722.6 fluid changes. I would personally change it every 60k miles or so to get some clean fluid in there. It is a special synthetic fluid that does not burn as quickly as conventional fluid so it really does not need to be changed every 30k miles.

If you have an earlier build 722.6 ( I forget the cutoff year but I think its around the 2001 area) it still has a drain plug on the torque converter which will allow you to get just about all of the old fluid out and replaced with new fluid.

DCF · #8 10-28-2005, 01:55 PM

Quote:

Originally Posted by blueranger

my transmission is at 247k and it is about to die.. so i am currently
changing it weekly.... trying to squeeze some more miles out of it..

i would not pay 100 dollars for a car with 110 k miles that had never
had a transmission fluid change....

Why do you think that changing the ATF weekly is somehow keeping your dying transmisison running? If it is already worn out (which would not be surprising based on the miles--although that is impressive) how is constantly replacing the fluid helping? Also, if you are using the proper fluid (MB synthetic) you have probably paid more for fluid, gaskets, filters and such over the past year than the cost of a new transmisison! If you are not changing the filter by dropping the pan, and just doing a pump out, all you are doing is wasting time and money, as the magnet and filter are still going to be loaded with metal. Since the fluid never gets old enough to get bad, your changes serve to only drain your wallet.

blueranger · #9 10-28-2005, 10:34 PM

i am using mobil one atf synthetic...
the reason i am changing my fluid is that i have
an electric suction device and it takes out about 3 qts
at a time... in addition... i am using the synthetic atf
and trans x to swell the clutches.... so yes it actually has
improved since i have been doing this...

i have found a used tranny and the fellow tells me he can put it in in a couple of weeks...