1999 S500 with 722.6 Automatic Transmission Filled for life?
 

How often should a transmission service be done?

if you do a search under 722.6 transmission you'll find a widely agreed upon figure of fifity thousand miles. expect something in the four hundred dollar range, and make sure either a dealer or mercedes specialist shop works on the gearbox. you can also think about an oil analysis from the drained oil to get some detailed info on the box.
I think the latest edition of Mercedes Enthusiast Magazine has an article by LJK Setright of Mercedes transmission, I haven't read it yet.

No transmission service is recommended on the 722.6, I don't recommend it, not until probably over 200,000 miles.

Gilly

Yeah, you're 1998 has the 722.6, so something is wrong in regards to the spec for a 60,000 mile trans service. MB never recommended a 60,000 trans service that I am aware of anyways, so something is wrong here. They went from 30,000 to lifetime. Is the spec you are quoting possibly out of some literature the DEALER put in the paperwork, not Mercedes??

Gilly

That trans should be serviced! Don't listen to MB about lifetime fluid, there isn't any such thing! If the trans is serviced it will LAST 200K to 300K.
WE (dealer) have replaced/repaired at least 2000 of the 722.6 transmissions in the last 2 years! Spend the money.

And in this corner...

This is where I would like to fly to Germany, find the 722.6 engineering team, and throttle them! Service it, don't service it. "Life" means what? Life of a lease, or life of the rest of the car?

Crap.

I can personally attest to a 722.6 going over 350K (miles) without being serviced at all (it was still going strong, I've lost track of the car now)
I do/did have a handout from MB concerning this topic, maybe it's time to try to dig it up and copy it down.

Gilly

OK, here it is verbatim:(comments in parenthesis are mine)
 

Filled for life?
The 722.6 Automatic Transmission uses a special oil and is said to be filled for life. The oil can only be purchased through the Mercedes-Benz dealer using part number 001-989-21-03-10. A 722.6 holds about 9.3 liters and the fluid is sold by the liter. Checking the fluid is accomplished by breaking off the red locking seal located at the dip stick. the lock is replaced after the oil is checked. Use part number 140-991-00-55 for a new lock. There is no dip stick to check the ATF. You need a special tool to check the fluid on all 722.6 transmissions, part number 140-589-15-21-00. The oil level is a critical factor in transmission shifting. See Service Information 27A95105 for details. When you refill, or check thetransmission fluid level make sure that you check the level with the special tool and at the correct temperature. The latest information from Germany is that we should fill the oil to the MAX line. Not overfilled, just maxed out. This is said to improve shift quality. At normal level it is possible for the oil to form air bubbles. The increased level helps to minimize this. You might want to remember to try this on customer complaints involving shift quality before you replace any component. Along with setting the adaptation you would be surprised to see how much of an improvement you will see.

The Automatic Transmission fluid is said to be filled for life. We never specified who's life. (Yes, they actually wrote that in this!-DG) The transmission control module contains a program that keeps a running count of the "calculated" cndition of the ATF oil. (Note from Gilly-I believe this was deleted from the modules right around 2001-2002, not there anymore-DG) The factors that affect the oil are time and temperature. The counter is incremented with engine running time and incremented greater with higher ATF temperatures. The Hand-Held Tester (now SDS-DG) displays a numerical value that represents the value of the calculation. At some given point in time Germany will tell us (still waiting, evidently-DG) which number means its time to change the oil. For now there is no service interval for the ATF oil. If you replace a transmission you should re-set the counter back to zero to account for the new oil. If you are doing internal work and you are replacing the oil you should also re-set the counter. It is acceptable to drain the oil out into a clean container and reuse it, provided it was collected using the MB filter funnel. Remember to flush the converter and kines before installing the new transmission. You should also replace the converter if the transmission was HEAVILY contaminated with metal. Make sure you return the converter with the transmission to warranty. Fine metal particles in the bottom of the pan are allowed. (I think what they mean here is that fine metal particles are considered an "acceptable" condition, do NOT replace transmission, as you will see if you read on:-DG)

The Color of Money:

We have been conditioned to judge the quality of the transmission fluid based solely on it's color and smell. We have no way of judging the frictional quality. The rules have changed. (didn't Iaccoca say that too?-DG) The bright red color that we are all used to seeing may not be what you see when you look at the ATF in a 722.6. The reasons that the oil looks differently are as follows:

1) The oil may appear dark red due to the graphite material that the friction discs contain. This does not change the characteristics of the oil. Do not change the oil or transmission if the oil appears dark red or even if it has a yellowish tint to it. The color will change with time and temperature. As of 10/97, the manufacturer of the oil has agreed to put more red particles in the oil.

2) If a copper color is seen in the oil pan the bushings of the front or rear planetary gear set may be in the process of wearing out. Inspect the bushings and if they are defective replace the complete transmission. If they are not defective, then the transmission is repairable.

3) If a silver color is present in the oil it may be a clutch and steels moving up and down on the hub as they are being applied. This is normal! Use your best judgement here. If the particles are fine they should not cause problems as they will be trapped in the filter. The fluid could be drained, including the torque converter, and the lines flushed and the valve body should be disassembled and cleaned, replace the filter of course. This usually takes care of the problem. If you take the time to inspect and clean each slide valve for ease of movement and base position you will have a better valve body than a new one from spare parts. In more severe cases where the particles are large, then something is in the process of self destruction and the transmission should be either replaced or repaired. Don't forget to check the electrical solenoid valves. Shine a light through the top of it and see if it "leaks". If you drop the transmission oil pan (I think they mean "remove the pan"-DG) and you find yourself feeling like a miner panning for silver, or knee deep in a graphite colored mud, then it's time for a new transmission. You may have noticed that the new pans are painted black on the inside. The metal particles show up better against a black background as opposed to the previous unpainted silver pan. You must get used to seeing some metal in the bottom of the the pan, with this transmission this is normal.

4) Smell the oil. You know by now what burnt oil smells like. If it looks burnt, and it smells burnt, then its burnt.

Example: Try looking at the adaptation values for K3. If the numbers are high, then you have a K3 problem. If the customer is complaining about shift quality going in and out of third gear, repair K3.

5) Make sure you understand the complaint before you disassemble the transmission. Use the HHT (SDS now-DG) adaptation screen values along with the shift application chart to see which shift members are applied during your customer complaint so you will know where to concentrate your efforts when you disassemble. Remember to disassemble the transmission like a surgeon, you need to observe the condition of seals, rings, c-clips and shims as well as being aware of the potential for missing parts.

Repair or Replace:

Use the transmission oil pan as an indicator when deciding to repair or replace the 722.6 transmission.

The following pictures (sorry folks, I'm transcribing the written part only, no pictures-DG) are for reference as to which transmissions should be replaced and which should be repaired.

(picture shows a black pan with some small "dots" here and there-DG) This is a normal oil pan for a 722.6. The fine particles are normal. Do not replace this transmission.

(can't tell what's "wrong" with this picture-DG) The brass colored particles may be a sign of a bushing problem. This transmission may be repaired.

(can't tell by the next picture either what the problem is supposed to be, rotten copies!-DG) The metallic sludge indicates that there is a major mechanical problem. This transmission would probably cost more to repair than to replace.

(This picture you can see obvious copious amounts of metal shavings, a pretty good coating of it-DG) This picture also indicates internal damage has been done. This transmission would be replaced (as well as the TC and flushing lines and cooler, etc-DG).

++++++++++++++++++++++++++++++++++++++++++++++++++++

OK gang, I'm all "written out" for now-enjoy!

Gilly

LMAO!!!!!

Thanks Dan for all the info!

Super post.

Thanks Bill.
I've had time to more or less digest my own info, and let my fingers uncramp. MAN I hate copying stuff down, much better not trying to copy down someone elses "stuff".

So what does this all mean? They say "filled for life", yet refer to this condition counter which they STILL haven't come up with the "magic number" for, and have even stopped putting into the newest control modules. It's alot of good info, but too many unanswered questions, such as why did they start installing magnets in the pan if a little metal is normal, and put the plastic shields over the electronic solenoids? And as a contradiction, they also stopped installing the torque converter drain plugs, so you can't, in my opinion, even do a proper trans fluid change. Unless you want to do a flush of the transmission like lot's of other cars have done, but I'd be really leary of doing that unless the flushing machine is dedicated equipment for the 722.6 fluid (don't want to get the wrong fluid into it somehow).

My opinion, and the reason I guess I don't really recommend doing a change, is that it just seems like if the transmission is going to "cash in it's chips" early, it just "is". Maybe I seem like some sort of "fatalist" by saying that, but that's how I feel about it. If there is/was something inherently wrong with the transmission (some tolerance set wrong for example, or an out of spec part), then it's GOING to fail, trans fluid replaced or not. Removing the pan may be a way of seeing it "coming", but I don't believe it will truly extend the life of the transmission.

Gilly

Yes I agree you should change the fluid and filter including draining the convertor 60k seems to be right. Being a GM tech for 16 years I can not see any fluid good for life. GM's Dex-cool is supposed to be good for 150,000 miles but I've seen that turn brown at 10,000 miles. They say the fuel filters shouldn't be changed until 100,000 and I've seen them clogged at 30,000.We are talking about a transmission and all transmissions wear I don't care what kind of fluid they use. The only reason they say good for life is to please the custumer when they purchase there new vehicle. It's a selling point MB uses. They say and I quote "and by the way you will never have to service the transmission in your new car which will save you money in the long run" and I have heard them say it. I just changed my fluid and filter in my 98 sl500. I purchased the filter, gasket and 8 liters of fluid from MB dealer for about 125.00. I also bought the special dip stick online for about 35.00.I got to tell it was one of the easiest trans services I have ever done. I think there were only six bolt or eight bolts. Anyway I just thought I give my 2 cents worth.

EAL=Eastern Airlines and Borman is Frank Borman? Man, you go way back! I read his book. I OWN a copy of that book!
I'll have to see if I can reference "The Colonel" saying "The rules have changed" (sounds like something he'd say though!), but I was referring to among the last batch of ads that Lee Iaccoca did for Chrysler, I think it was for "cab-forward" design. What was that on, the Chrysler Concord? Or was it that Herman what's his name doing cab-forward?

Gilly

Yeah, he seems to have LOTS of nice planes, or just keeps getting them restored and selling them. I know he did or does have a real nice P39 or P63, I think it's a P39 though. All named "SU-SU" for his wife Susan.

I can see you're into the old NASA days as much as I am, I've heard (and understood) that quote by Jim Lovell also. What are you doing for NASA? That's interesting.

Thanks for your comments.......

Gilly

Nice write up Gilly, thanks for sharing Mercedes thoughts on 722.6 transmissions.

I have changed my trans fluid at 80K miles. I found a thin layer of sludge on the bottom of the pan. I also installed the pan magnet since my trans is an early build. The main problem I see with the "fill for life" attitude is that Mercedes has used a very small transmission filter for this vehicle. If I left the original trans fluid in the vehicle, eventually the sludge could have plugged up the filter and overheated the transmission causing an early death (in my opinion).

I usually keep my vehicles for 200K miles at which point the body is falling apart. The engine and transmissions were original and running strong on the last two vehicles that I donated. My theory is to replace fluids and filters on a scheduled bassis. With synthetic fluids I have extended the intervals out but still replace them because the filters and fluids still get contaminated.

If synthetic water existed would the "fill for life" advocates never change their bath water?

LOL!! "Depends on how good the filter is" I guess!!!

Gilly