early 722.9 mandatory service? - PeachParts Mercedes-Benz Forum

Will_w202 · #1 04-28-2008, 04:24 PM

Question is.....I recently acquired an 8/05 production C 350 with the auto, and it has some jerky shifts, moreso than on my old 722.6. Was the newer-style (3353?) fluid used from the factory in this trans from inception? Also, I am wondering about the best way to approach my SA about it. Am I likely to get an early fluid/filter change under warranty, TCM flash, or what? Can't find much info in here on the 722.9, suppose because they're still in the warranty period and not many DIYers posting here about them

mbdoc · #2 04-28-2008, 04:48 PM

60K kilometers (39K miles) is the recommended service change.

There have been at least 7 flash up-dates for that trans.

IN most cases the engine computer also requires a re-flash at the same time.

Will_w202 · #3 04-28-2008, 05:13 PM

Whew! 7.. sweet. I'll make an appointment and look forward to the results. Thanks Doc!

ILUVMILS · #4 04-28-2008, 08:43 PM

Quote:

Originally Posted by Will_w202

.....I am wondering about the best way to approach my SA about it. Am I likely to get an early fluid/filter change under warranty, TCM flash, or what?.....

For some reason, the C-Class MB's have had far fewer transmission issues than the other models. The ML's and R's seem to have more problems, IMHO.

Just tell your SA that the transmission doesn't seem to be shifting as smoothly as it should, and let him/her worry about it. The diagnostic process isn't all that complicated. They'll start by checking the basics (ATF level and condition, fault codes, etc. ) and proceed accordingly. The majority of shift quality issues are solved by updating the software in the engine and transmission. Sometimes the valve body needs to be replaced with an updated version. Now and then, the transmission needs to be replaced. If your car needs more than a software update, your dealer will need to obtain pre-authorization from MBUSA. Yes, you heard right, pre-authorization! . Since there are only a handful of factory-approved repairs for the 722.9, MB wants to be "kept in the loop", to help control warranty costs.

In your case, it sounds like the new software will take care of your problem, but there's a chance you'll need a new valve body. If this is the case, you'll get the fluid changed, but not the filter, MB Warranty simply won't pay for it. I know it sounds ridiculous, but that's the way it is.

Let us know how things work out.