ML320 Tranny Service - PeachParts Mercedes-Benz Forum

Lewis · #1 10-22-2002, 01:21 PM

Gilly,
You mentioned in a previous post that MB wants a few things done in the 722.6 trans if a tech goes into it for any reason. I, like a lot of other nervous ML owners, am considering a trans fluid change about the 55-60K mile point and was wondering what the "things" might be. Is there a filter involved (I would think not with liftime fluid)? Is the fluid change done with a suck and fill thru the dipstick or does a plate or pan have to be pulled off exposing tranny innards and then be resealed? Do the "things" to be done items consist of just adjustments or are upgraded parts also involved (will I have to pay for them or is this a tech bulletin?)? Lastly, is this job something I should ask for my shop's Master Tech to perform, or can any of my dealer's techs handle it?

Gilly · #2 10-22-2002, 10:32 PM

There was a few changes made. one is the addition of a pair of plastic caps over the electronic shift valves. Very inexpensive parts. I don't have the trans number breakdown of when they began installing them at the factory. If you have a 98, especially an early version built in 97, chances are it needs them. The valve body needs to come down to see if it has them or not and to install them if neccesary.
There is another addition, a magnetic pad about 1/2 the size of a playing card, just drops into the pan. Another cheap part, should be "0" extra time for this.
For the caps i could see an extra 1/2 hour to 1 hour labor to check and install these if neccesary.
The magnetic pad I believe went into production roughly beginning of CY 2001.
Yes, there is a trans filter, again not a very expensive part. The fluid is pretty expensive though.
It is not sucked out, the pan is drained and removed in the regular way. An earlier version will have a torque converter drain plug as well, the engine is rotated via the front of the crankshaft until the torque converter drain is visible through the access hole in the bellhousing. I believe the drain hole on the torque converter was eliminated beginning with the 2000 models.
I fully believe you would be responsible to pay for these changes.
I would say only if you really plan on keeping the truck many more years that you would consider doing this service, and even then I'd wait to closer to 100,000 miles.

I don't know how to respond to who you should have do the work, whoever you want I guess is as good an answer as any.
Or if you find that one of the techs has been through the 722.6 class lately, he may be the guy to ask for.

Gilly

Lewis · #3 10-23-2002, 12:56 PM

Gilly,
Thanks for the info. Sounds like fairly minor mods, I may cross my fingers and try to hold out longer on the fluid change and upgrades. My ML is a very early 99, so it likely didn't catch most of the upgrades. I had a new xfr case put in under warranty at 46K due to binding and shuddering on tight turns and now have 52K with no tranny problems yet. Anyone out there had a trans problem, at what mileage?

Gilly · #4 10-23-2002, 06:01 PM

We have a service advisor at work with a 97 E300D with at last check 280,000 miles on it and the transmission fluid on his 722.6 has never been changed, working great. He bought it with about 225,000 on it from a customer of ours who bought it new from us and did all the maintenance specified by MB. That same customer is now into a 2000 ML320 and is approaching 150,000 on that with nothing but the normal FSS schedule maintenance work done, and it's doing great as well. He likes the ML but really wants a Diesel again. Nice guy, he and his brother are travelling salesmen. I believe they sell books to schools, textbooks and library books, like that sort of stuff. Lots of books in the vehicles when they show up, they empty them out id they bring them in for service.
It would take me 8 or 10 years to put on a couple hundred thousand miles. If I were going to do that with a vehicle witht he 722.6 transmission, I would probably do the trans service at 100,000. MOST people don't hold on to a vehicle for this many years or miles.

Gilly

KyAl1013 · #5 11-18-2002, 07:45 PM

Gilly,
You're saying that you'd recommend waiting until 100,000 miles before servicing the transmission on a 722.6? Would you wait until then to do the magnetic strip and valve body caps too? Also, would you still recommend the 100,000 service interval if the car does not get very many miles? My 1997 E320 has only 36,000 miles on it and I think it will be around 6 more years until it hits 100,000. Should I have this trans serviced at some point before 100,000 just due to the time? Were the earlier 722.6 (1997-1998) more problematic or shorter lived than the later units? Thanks Gilly.
Kyle

Gilly · #6 11-19-2002, 09:59 AM

Kyle:
Yes, as a general rule I'd do it at 100,000 miles, only if, as I stated before, you are really planning on holding on to the car a very long time. To change it if you don't plan on holding on to it is a little like the guys who use seat covers only to protect the seats. Why not enjoy the seats? Well, maybe a poor example, but I think you know what I mean.
On the second part, if it get low mileage. I guess if it were a case where it accumulates lower mileage because of numerous small trips, I could see maybe doing it sooner. If you are bound and determined to change that ATF, then don't let my advice hold you back! But if the car is driven normally, but only ossasionally, then I'd stick with my "100,000 miles if you are keeping it forever" advice.
There were some manufacturing problems with the earlier boxes, nothing that changing the ATF will help with.
Yes, do the magnet at the ATF change.
Gilly