HLSD

Just got word from the dealer that the star diagnosis machine says that my adaptation data is way, way out of whack and that the only cure is a new transmission, torque converter etc to the tune of $7500. My car has a little more than 41K miles. Here is the story:

I bought my 99 C43 just over a month ago at Carmax. At the time I also bought a Maxcare extended warranty that basically covers all non-wear mechanical components. During the first few weeks I brought the car to my local MB dealer to have all fluids changed and to have everything just generally looked over. I had the dealer do the pan magnet upgrade when changing the transmission fluid. The dealer said everything looked great, except that I probably needed one new engine valve cover gasket.

After the service I began to wonder if there was something wrong with the transmission. Two times I actually bounced off the rev limiter in first gear after a kickdown from 2nd gear. It seemed like the car's computers were misjudging how much rev matching was needed to accomplish the kickdown, flaring the engine up to high rpm, and then not shifting fast enough to avoid the rev limiter. I took the car into the dealer but we could not duplicate the problem. I was told not to worry as the Star machine said the tranny looked fine.

Yesterday I brought the car in to have the valve cover gasket done, and asked that they check the tranny again. So that's when I got the bad news that the whole assembly needs replacing. Even worse news was that Maxcare won't pay for it. Their position is that the problem existed during the first 30 days that I owned the car (they know that I talked to the dealer about a transmission issue) and so should have been covered by the selling dealer Carmax. Of course I didn't take the car back to Carmax, as there was nothing diagnosed for them to fix (even if they could have managed the job), and now I am past their 30 day standard warranty period. I think I seem to be in danger of falling through a crack between Carmax and Maxcare! A Carmax service advisor left me an encouraging message yesterday, but then again he hasn't seen the size of the repair bill yet.

I'll let you know how it turns out.

C43AMG

That number is wayyyyyyy out of whack ........$4k........TOPS.

Vardar

I feel for you! Last(it really was the last time) time I took my car to the dealer for oil change. They came up with all kinds of crap that needed to be done. I freaked out and felt like someone poored hot water over my head. I took the car to this mechanic that worked in Mercedes factory for 30 years in Germany ( I wish i heard of him before). He said that's what dealers do. Everything was fine. Your case is different, cause you are feeling some unusual stuff.. I would advice you to find experienced foreign car mechanic mechanic with a great reputation, and get a second edvice.

GOOD LUCK!

1badamg

That really sucks. I talked to a fellow in my area who had a tranny issue and needed it replaed. He said his bill was about$7k. Correct me if i'm wrong, but aren't most tranny issues only with the 98's?


And would anybody happen to know if the extended starmark warranty would cover a tranny failure?

1badamg

Hey HLSD, check out this site. They are mbz dissmantler. They have tons of cars and parts. They are local in my area, but maby you could find one in yours. Not sure if there are others.


www.silverstardismantlers.com/

C32AMG/02

Do you have a print out of the adaptation data, fill pressure , fill time and shift time, if not ask for one. That information is an important diagnostic tool. A low transmission fluid level will give a false adaptation reading; have another shop verify the fluid level, they changed the filter and fluid. I would have it checked.

The early generation 722.6 transmissions, has undergone several design changes; mainly to the valve body, conductor plate and soft wear flashing up grades.

The pressure regulator spring is one, it breaks causing low working pressure, and maybe it’s the cause of the slipping, which would set a high adaptation value. Do you know of any warranty work done to the transmission. Post the print out if you get it.

knvs

NO that number is correct.... i had mine replaced along with several ppl on this board and it was close to the $7k mark. Now if it was a tranny rebuild then yes $4k tops...

C43AMG

Ok, why would you have to have it replaced as opposed to having it rebuilt ?

C280Sportster

Dude, most aftermarket warranties try to wiggle out of repair work (standard procedures maybe?). I think they are full of crap. Talk to a lawyer about this, maybe one letter will be enough. The car was always under someone's warranty, you were always covered and they need to pay, not you. You also have the BBB and other consumer protection agencies.

Any lawyers here willing to help? Maybe someone here will help and you can give them a few $100 bucks.

knvs

The C43 tranny is a sealed unit and many repair shops will not open it up. Thats why most of the trannies are replaced instead of rebuilt. Or that what my mechanic said. I actually got a quote from the dealer to replace my tranny for $7800. Luckly the shop that did my swap had the matching E55 tranny so I just swapped that one in for much less then what the dealer was charging

Waynec1980

Sorry to Hijack this thread but I have one small question.

My car is slipping.

It only does it sometimes but I am afraid to drive her fast incase I do more damage. Do you think it is as simple as this spring and is it easy to fix??

Thanks in advance

Wayne

ProjectC55

I agree!

HLSD

Folks,

Thanks for all the advice. I just got back from a week's vacation where I didn't have the opportunity to follow up with Carmax or the warranty company. Carmax left me an encouraging message when I was gone, so there is hope there.

I will try to get the adaptation data and post it. I had the transmission fluid changed within a week or two of buying the car, and I noticed the shifting problems only after the service. I actually brought the car in after the service to have the fluid level checked, as I wondered if underfilling was the problem. The tech thought the level was too high at the time and so pumped a small amount out. He seemed to be careful in checking the fluid level, but I noticed that he did not measure the fluid temperature when doing so. Anyway it was at that point that he cleared my adaptation data and sent me on my way. A couple of weeks later the adaptation data was apparantly reading quite high ("nearly 200" is all they told me), and that is when the tech made the diagnosis of impending transmission failure.

Riffyb

why dont you try the adaptive ECU reset .. its worth a shot

c55m8o

Something I read here is wrong. The tranni is not a sealed unit. I had mine worked on 3 times (or was it 4?). Had the valve body worked on, and even had the clutch paks worked on 2 times. I'd have to dig out all the service receipts to list everything I had done; but you definitely can't do that stuff if the unit is 'sealed'.

Do you have a 2nd or 3rd car? Get AAA then, and just let it break before doing anything. And boy do I know it's tough, but find another place then a stealership now, in preparation if it is going. Look for hi-end tuner shops in your area. There are even good indi tranni shops that are very capable. Yes, they are tough to find, but I found both with help from others.

BTW, are you sure your MAF isn't bad...

C32AMG/02

According t o MB, adaptation data should ONLY be reset after any major transmission repairs and only if the transmission control module were also changed.



After clearing all adaptation values you have to do a one hour drive cycle of stop and goes, different road speed and rpm ranges, up and down shifts, to teach the TCM the new adaptation value of the transmission.

How long it takes to fill the clutch drums and more. These are base setting, once you drive the car, the TCM will adapt/ learn your driving style and adjust accordingly.

The tech which serviced your transmissions has little or no experience, the filter has to connecting points, one in the front the other in the back of the filter, since your transmission problems started after a service, it’s in your best interest, money wise too check his work,

I would remove the transmission pan and make sure the filter is installed properly; o ring installed in the filter neck and fasten correctly. Also check the fluid level at 80C.

Those are the first steps I would take if your car were in my shop, base on the information you provided.

C32AMG/02

The spring can be checked / removed, changed with the transmission in the car. I will post the procedure with pictures this week end.

C43AMG

IMHO, I would be looking for a new mechanic if I were told this.

Waynec1980

Thank you very much that will be very helpful.

HLSD

I took my car to an independent MB shop today. I made sure the tech used the Star computer to check the temp of the transmission fluid, and it turns out it was about half a quart low. I also wrote down all the adaptation data that we could find (see the details below). The tech had no experience in interpreting the numbers, so I would be very grateful if an expert like C32AMG/02 would give me an opinion. I had the tech drive the car and he did not detect any clutch slippage or other problems during the road test.

I guess I have put about 350 miles on it since the dealer made the diagnosis that I need a new transmission. Naturally, I am wondering if the thing is broken at all. As a next step, I could have the independent shop drop the pan and check the filter and seals and look over the fluid to see if it has much in the way of metal shavings.

BTW, it seems that Carmax may opt to buy the car back rather than pay for a new tranny. So I will soon face the decision of dumping this car, which I love, or bearing full responsibility for the transmission.

Thanks in advance for any good advice!

01 accel 1-2 -45 -87
-78 -18
-12 0
02 accel 2-3 -12 -21
-57 -24
0 0
03 accel 3-4 -6 6
-57 -42
-3 -24
04 accel 4-5 -36 0
-87 -12
-15 0


accel 2-1 -30 0
-9 0

3-2 -129 -81
-21 0

4-3 -81 0
-15 0

5-4 -138 -6
-48 0


Fill Press. 1-2 -540 mbar
2-3 -380 mbar

Fill time K1 in 2nd gear 0 cycle
K2 1 cycle
K3 3 cycle

Fill time B1 0 cycle
B2 6 cycle

K1 in 4th gear 2 cycle

HLSD

Here is a link to information on a replacement pressure control valve spring for 99 and earlier 722.6 transmissions.

http://www.transmissionspecialty.com...s/68942-01.htm

There is a link on the page to a pdf with detailed and illustrated instructions. Apparently there can be all kinds of difficulty with the transmission if the spring breaks, as they are prone to do.

Maybe it would be a good idea to have the little bugger checked during a transmission fluid change. I tried to get my independent mechanic to do it, but he didn't feel knowledgeable enough to try (this despite 22 years experience working on MB). On the bright side, I did succeed in getting the filter re-installed correctly; i.e. with both front and rear attached to the valve body. My car seems to shift perfectly now and there was no metal or graphite or anything else expect oil in my transmission pan, so maybe my car will be ok despite the dire diagnosis from my local dealer.

C32AMG/02

I apologize for this late post , it has been a hectic work schedule



Accel 1-2 shift time Adaptation data

-45 = High load, low rpm -87 = High load, high rpm.
-78 low load, low speed -18 = low load, high rpm.

-12 very low load, low speed 0 = Neg. load, high rpm.


02 accel 2-3 -12 -21 03 accel 3-4 -6 6
-57 -24 -57 -42 0 0 -3 -24

04 accel 4-5 36 0
- 87 -12
5 -0




Shift time is the ability of the transmission control module to change the time it takes to shift from one gear to the next. The six numbers for the 1-2 shift indicates the correction factor,– or + values at different transmission output speeds and engine loads. Zero adaptation means, adaptation did not happen or no adaptation was needed or necessary.

Without a scanner or true print out of the data we cannot view engine load and transmission output speed.

Changes from a low to a higher value indicates that the TCM is decreasing fill pressure to lengthen the apply. Changes from a higher to lower numbers indicates that the TCM is increasing fill pressure to shorten the apply, a harder shift


the -87 =High load, high rpm load reading for the 1st to 2nd Adaptation is set near the middle of its max negative adaptation value.





Fill pressure 1-2 -540mbar 2-3 – 380 mbar



Fill pressure: the strateregy give the TCM the ability to control and modify the pressure used to engage a clutch, meaning shift feel, harsh or soft. The max adaptation is + or - 1600mbar.









Fill time adaptation

K1 in 2nd gear
K2 1 cycle
K3 3 cycle
B1 0 cycles
B2 6 cycles





Fill time adaptation is the time that it takes to fill a shift member(clutch drum or applying a brake band) taking all the clearances up but not applying the shift member.

This adaptation compensates for wear of the clutches, the amount of steels and the clearance between them, and leaks in seals or filters installed incorrectly.


Hydraulic pressure begins to build in the applying piston while at the same time the pressure regulating switchover valve are regulating its supply pressure . The pressure regulating switchover valves are controlled by an amplitude modulated signal from the TCM.



For 1st gear the B1, B2,and the K3 is applied

For 2nd gear the B2, K1 and the K3 is applied

For 3rd gear the B2, K1, and the K2 is applied

For 4th gear the K1, K2 and K3 is applied





K1 in 2nd gear 0 cycles = no adaptation

K2 1 cycle = 20ms period
It took 1 periods of 20 millisecond of signal to alter the pressure enough to correct the application of the 1st to 2nd shift.


K3- 3 cycle = 60–ms period, it took 3 periods of 20 milliseconds of signal to alter the pressure enough to correct the application of the 1st to 2nd shift and 4th gear


B1 0 cycles= no adaptation needed
B2- 6 cycles =120–ms period, it took 6 periods of 20 milliseconds of signal to alter the pressure enough to correct the application of the 1st to 2nd shift, and 3rd gear







By looking at this data we can conclude that the 1st to 2nd gear shift needed the most correction to optimize that shift.

There are no ideal numbers, if the adaptation is at its maximum value, and the shifts are slipping, flared the transmission needs repair work. The numbers for the others gears does not indicate much adaptation was needed. Amazing for a transmission that was low on fluid, and the filter was installed incorrectly.

C32AMG/02

[IMG]





It would be a good idea to change the filter and pan gasket while you are in there.
The done side about haven this style spring is that you don’t have, an up dated valve body and TCM. Also the valve bodies and TCMs are match to each other and are not interchangeable.The 722.6 transmissions use a special fluid /oil.



If you have a 1995 to 1999 MB with a 722.6 transmission this information will apply to your car if it has an early valve body.


Torque values: pan bolts 8Nm, torque converter drain bolt 16 Nm

HLSD

Transtech,

Thanks for sharing your expertise on this topic - I found it very helpful and am sure others did too. I just got back from a 1300 mile trip in the C43. No problems after the last transmission service, so I am going to knock on wood and keep driving

HLSD