Okay folks, this is by no means scientific, but the topic has been bandied about on the various sub-forums and I was hoping to get a better handle on it and I figured the General forum was the best place to gather information since it affects hundreds of us members.
Some of this is informational and some is advisory; hopefully more than a few of you will find something useful and practical in this post.
As many of you know, the 722.6xx 5-speed electronically-controlled automatic was introduced ca. 1997 and is in most of the MB lineup. Originally marketed as "maintenance free" the transmission came with a dipstick tube and a cap with a tamper-proof locking clip (which broke if disturbed, if the tab is missing or the locking pin is red/orange it's been opened, perhaps just to check fluid after replacing the leaky connector discussed next). Just to check the fluid you have to buy a dipstick tool.
Many of you are also aware that the transmission has an electronic adapter/connector on the front right that is prone to leaks (for those of you who aren't, please check yours!)
(As an example of this issue here is a thread with pictures: http://www.benzworld.org/forums/w210...connector.html
In addition, the early years of this transmission had a problem with the pressure regulator spring that can break, resulting in slipped upshifts; here is an example of a thread discussing that topic: http://www.benzworld.org/forums/w210...er-needed.html
Very close to the introduction of the 7-speed automatic, MB changed its recommendation with respect to the final model years of the 722.6xx transmission, recommending a fluid and filter change at 39,000 miles.
As a result of failures and transmission symptoms, many owners chose to ignore the "maintenance free" marketing and have their transmission competently serviced. This means using MB parts and fluid, not "experimenting" with other things, and setting the level properly. Largely anecdotal evidence in nature, these people report smoother operation of the transmission thereafter. At least one member sent his fluid in for analysis after a service at 59,000 miles and posted the results. This is the link to Musikmann's excellent thread, which has a good bit of useful information in it: http://www.benzworld.org/forums/gene...n-service.html
His particular post with his analysis results is here: http://www.benzworld.org/forums/gene...ml#post2184801
You can read the analysis for yourself, but it shows fluid contamination/degredation (as might be expected).
So, coming to the point of this poll...
Please make your choice from the options above, picking the one that makes the most sense. Due to limitations of the forum I couldn't build the poll the way I'd prefer, but I think it will yield some useful data. The poll is private so you won't be able to see who voted which way.
Please, I beg you all, try to restrain yourself and DO NOT turn this into a debate about whether
to service the transmission, those threads tend to lead quickly down the rat hole and serve no useful purpose. If you must comment on that unrelated issue, please start your own thread/poll and don't hijack this one.
However, if the poll options do not describe you (for example you serviced your transmission with non-MB fluid) then please go ahead and post to that effect. If you suffered a failure please post the details of that as well (and if you spilled coffee into your center console, you can't blame that on the transmission, but detail it anyway
I think that's it. I hope we'll all find this to be useful information as it develops over time.
Take care and enjoy the ride,