Mine's been standing up to abuse including regular WOT highway-speed downshifts (exercise) for 145k miles.....knock on wood

Fluid/filter every 40k.......yes all electronics and a conductor plate were done under warranty, but the basic mechanical internals are 10 years old and perform flawlessly to this day

If you have one that's defective, I think it would have been evident before now. If you've got over 50k and 5 years on a 722.6, and it hasn't grendaded, you don't have a defective tranny........if it dies at any point after this, it's because YOU didn't maintain it properly

A bit of relief to hear. Mine is all original except the fluid done at 52k when I bought it. Although now it slips once in a blue moon (when cold) from a standing start. It would do it only once a day and its when its still all cold and pulling away.

180,000 miles on mine, and nothing but a whisper from it.

No fluid change yet, Parrot?

"If you have one that's defective, I think it would have been evident before now. If you've got over 50k and 5 years on a 722.6, and it hasn't grendaded, you don't have a defective tranny........if it dies at any point after this, it's because YOU didn't maintain it properly."

I read statements like the one above, and just get this puzzled look on my face. My mind says, "Really?"

The writer's logic starts with a declaration about 50K and 5 years. Exactly where did those statistics come from? Then the assertion that the defect either exists, or does not exist. Where are the facts for this statement. Thought it was stated by the pro mechanic that it was a design defect, not a defective part. In other words, you can have a perfect part that is not up to the task and fails over time.

Finally, we get a pronouncement that death after 50K is your fault due to faulty maintenance. Maybe, but you can find some pro's on this forum who disagree.

Within this thread alone, we have professional mechanics, who actually have some real data. Even their data is very limited as a percentage of all the 722.6's out there. It has been stated that the problem bearing has been updated to a bushing. I suspect the driving environment has a lot to do with the time before failure. Highway versus City.


My '97S320 has 116K. Tranny serviced at 65K and at 109K when I got it. I would not presume to reach any global conclusions based on the my data point of precisely 1 transmission. Working fine at the moment, but who knows what will happen in the future?
My logic is as follows. I got the car cheap, $12,000, relative to any new car I would even consider. If I have to buy a factory re-manufactured transmission for another $5,000, I'm at $17,000, still cheaper than any new car I would want to drive.


Steve

This debate is getting VERY useful !
Let me add a bit of poison, addressing a taboo topic:
Is there a known "super lubricant" ATF aditive that may help us on a preventive basis ?
I know and understand that manufacturers are adamantly against this. In fact cars are supposed to work with regular off the shelf stuff. (certificating aditives and their interactions with regular brands of lubricants may become a nightmare if a manufacturer tries to do it)
Using a special aditive to minimize a design flaw would NEVER be addressed. It would mean acknowledging the flaw...
Just for a starter: I remember the Molykote (molybdenium bissulfide if I recalls correctly) revolution back 40 years. It was not a detergent, an atioxidant etc: it was LUBRICANT. It dealt directly with friction reduction.
No need to say it was very polemic. (despite being widely used in race cars)
I remember it was not accepted in Porshe gearboxes because the synchro rings would sleep and fail to synchronize)
How about this vis-a-vis the current world + auto transmission environment ?
Do we have components that cannot be overlubricated?
Jorge

An automatic transmission is different from a manual transmission. Automatics have clutches that have to have friction to engage. Thinking about preventing this potential failure by some amateur hour addition of lubricating additives is just foolish.

Stay with what the manufacturer recommends. The manufacturer has invested thousands and thousands of development manhours in this transmission. They are smarter than we are relative to this subject. Logic says you should follow their advice with one caveat. The sealed for life thing is most probably a marketing ploy. I choose to service my transmission, but that is not the same as choosing to pour in some snake oil.

Steve

My friend has 175k+/- miles on his 722.6 and it's still shifting like new. AFAIK the fluid was only changed once, by him at about 150k miles or so. It did shift better after that.

Even the old MB trans usualy die between 200k-250k, if they are good, some much younger. My 300SD for example the PO rebuilt the trans before 150k miles.

So they seem like a fine transmission to me, last pretty long, shift real nice. The only downside is last I checked rebuilts were $3k.

Steve, there is no scientific research behind my statement. I'm not an expert. My grandmother's 98 E320 had the trans grenade at 30k years ago. I've been around this board and picked the brain of my own shop foreman at the dealer (while under warranty) enough to deduce that most of these rebuilds (MBDOC, etc, correct me if I'm wrong) occurred under warranty back when the 722.6 was newer/more of an unknown, and when fluid changes were not advised. Seems now the ones that the various techs on this board talk about seeing fail (in other words, the ones that have survived several years/10s of thousands of miles) are the ones that saw no fluid changes. If all 722.6s were POS units, I would have killed mine long ago. I'm not easy on it, but I am anal about maintaining it. Again, 146k so far...

I like the anal and easy on it points. I am the same way. The computer brain learns your driving habits. I try to play off that with my throttle habits. I have enjoyed the trannies in my 124's, but I really like the 722.6 better.

Hey, at least you have a good relationship with your shop foreman. Our dealership elects to run without a shop foreman. I really pissed off the head service writer just after I got the '97S320. It had been serviced at that dealership for 4 years and I have every record.

I simply inquired about having the transmission serviced. He cut me off with the sealed for life thing. Then he said it would be $450. I asked him whether he thought I was just plain stupid. Told me the filter was $75. Then I explained that I didn't buy the sealed for life thing and that I had their own service record for a tranny service at 65K miles. All the guy had to say was, "Yes, I understand your concern. We charge $450 dollars. You might want to take it to an independent shop." I left in disgust and haven't returned.

Steve

Another thing....I drive mine like there is a glass of water on the dash. Its just the way I like to drive a Benz....I also think this benefits things like transmissions as the shifting is barely noticeable when doing that. On the highway I always open it up.

Would driving it smoothly help things out?

Frequently, the problem may is as simple as an internal seal failing. There wouldn't be any metallic debris floating around internally, causing subsequent damage. In that case, if I were a brave DIY'er, I'd take it apart and see what happened. A seal kit is cheap, so while I was in there I'd replace all the seals possible. I'd also measure and correct the clutch clearances if necessary. If they were all out-of-spec, only six snap-rings would be needed to fix it. Cheap. And don't forget, the 722.6 is not that complicated. I think it's well within the ability of many DIY'ers.

On the other hand, if I dropped the pan and found a mess, I'd just bite the bullet and replace the entire unit. I'd also flush the cooler and lines as well.

Bought the car at 163,000 and did a change at 165,000 - I don't believe it had ever been changed before that. Minor improvement in gearshifts since.

The old fluid was as black as used oil.

Steve,

Conceptually could'nt agree more. Our problem is that in OUR case those many hours led to a faulty design. It happens and may have fixes or not.
I would never go after some "snake oil" wonder thing. We are in full sync on this.
My question is broader: is there a known addictive coming from a known brand accepted to help in some circunstances?
For example: Race cars, cars used in hot boiling deserts, car with extra high mileage, extra low temps, etc.

In general manufacturers may be skeptical but even they support some of these solutions. The concept of severe usage is in the owners manuals.
I consider that the lifetime thing is part of the past. Just for reasoning lets imagine that the accepted standard is now 5 years or 50K miles, whichever comes first.
Would a 722.6 be benefited if we divide the mileage by two ? (about 250 dollars more in 5 years)
Why not making official the installation of the pan magnet present in newer versions? it is so intuitive.
How about an extra cooling pump? (it has ben done before)
And, if (only if......) some addictive is accepted for specific situations what COULD be the effect of using it in a not so good vintage of trannies?
We are in a grey area. Officially , as far as I know, the issue is not even acknowledged by MB.
We don't know the figures but so many among us say they are doing great... at much over 100K miles...
I am concerned but at 48K my transmission is wonderful. Far better than the ZF in my Audi. (not plagued as ill)
I am fighting to keep it as it is... The shifting is the best I have ever known.
I can always say: If I only divide for 2 the change interval... as an educated guess ... I am ALMOST sure I will greatly reduce my risks. For how much $$$? Close to nothing.
I have much to lose if it fails. But LOTS to gain if the lifespan is increased by 25% in exchange for a 250 dollar oil change. If it is increased by 50% the issue is over.

On my side I made, so far, a set of decisions:
- 5 years most
- every 25K mile
- magnet in the pan
- every change=new filter

I don't live in a place whose market is able to evaluate addictives to expensive german cars. You are in the best one. (well, may be except Germany itself - which BTW would be VERY nice to hear of) (I mean - equivalent newsgroups)

Well - at least we are having fun...
Best Regards and thanks, Jorge

Save money on the additive thing. Specific lubricity is required for proper function of the transmission. If you alter that part of the equation, something else will probably give.

If you are concerned, simply change your fluid more often.

As we always say on the farm, dealing with extremely high stress lubrication situations: change it hot and change it often. If it breaks, get a new one.