Hello all, posting about my 2012 C63 and an ever longing transmission nightmare. I've heard of the 722.9 not being the best, but I've scoured threads in hopes to find someone with similar issues but have found nothing. First noticed issues about two years ago, the transmission started to over rev itself to get into the next gear. Had a Gintani tune on it so I took it off and the issue still prevailed to the point where the car stopped moving all together. It would freely rev as if in neutral. it had no forward or reverse gears. I removed the transmission myself to see if there were visible issues such as no fluid pressure, broken pump, dirty fluid etc. Found nothing and was.not going to crack the thing open myself so I took it to a shop. They said all the gears and clutches looked fine so just replaced the valvebody and conductor plate as well as the torque converter. Car then went to Mercedes to be reprogrammed and it seemed all was good... only for the same slipping to start happening again after about 3k miles on the new components. Car went back to said shop under warranty and they replaced the transmission entirely with one out of a 36k mile C63 and put a brand new valvebody, conductor plate, and torque converter in again. Then went back to Mercedes to be reprogrammed (somehow the car broke off a winch rolled out of the service bay and into a wall during the process) but after that the car was returned to me and was driving fine until it wasn't... the car started slipping AGAIN and would not move. The shop where I got it fixed refused to work on it anymore and just gave me a refund. So after it being in the shop for a collective total of a year and 4 months I'm still sitting here with a C63 that doesn't move. I just recently took out the transmission again in preparation to send it off to Southern Hotrod to get the war viking build but I don't know if this will solve my problem. Does anyone have experience with these certain issues? If so, what was the remedy? Thanks

 

That's some serious pain and suffering. With all that work, any mention of codes when scanning?

 

It's a very easy fix. Next time you get it properly fixed, stop ****ing with it with aftermarket tunes.

 

the tune was taken off even before the first "rebuild" and never put back on.

 

no codes relating to transmission at all

 

Usually when I see things like this I question if there's even a problem. Do you drive like a normal person or are you driving erratically and with 2 feet? No idea how removing your transmission would allow you to for no pressure. You could've loosened a transmission cooler line and verified that. Next you mention removing the tune after the issue occured (damage already done) then it didn't stop. So I'm betting you put it back on....Then got some repairs done seems like car was actually fixed and then the same issue happened again. If this car is not being used and abused well beyond normal intended uses the transmission would not start slipping. If my crappier one rated for less power can handle 30k miles of real abuse with a blower before having issues than it's either you or the tune are trashing it. Are you a normal amg aggressive driver or a clown? If clown it's you. If normal than it's the tune. There's a lot of really bad ones.

 

1. A 2012 C63 does not have a torque converter. They have a wet clutch pack -- so that's a load of BS in item (b).
2. Please explain why the car had to go back to Mercedes to be reprogrammed yet again after the transmission replacement in item (c) if it the ECU and TCU were already running the OEM coding after the repairs in item (b) were performed?
3. The shop that did the transmission repairs in (b) and the replacement and repairs in (c) was obviously incapable of doing the work if the car then had to go to Mercedes for reprogramming (and I am not even taking into account the "torque converter" replacement BS). That says a lot both about either their ability to service it as well as your ability to make sound decisions if you are in fact being truthful.

So far you have scored exactly 0.0% both on the veracity and the sympathy scales.

 

So...to make sure I'm following this order of events correctly:

1. Gintani-tuned C63 starts having shift issues. Did you have the car tuned or buy it that way?
2. Tune is removed, issue worsens.
3. You remove the transmission yourself to check things that could be done with it still in the car and then decide to drop the car and the now-removed transmission off at a shop to diagnose further.
4. Shop finds no root cause, throws some parts at it and sends you to the dealership for programming.
5. After that, all is well for 3K miles.
6. Issue returns, process with the shop and dealer repeats, warranty replacement is performed.
7. Car is fine for a brief period of time and then the issue comes back.
8. Shop decides that absorbing the loss is better than continuing to deal with you / your car and issues a refund.

The 722.9 transmission is surprisingly durable, but its fill / level-setting procedure requires precision in a narrow window and (depending on the model year / variant) there are different fluid specs and filter part numbers for it which, if you get wrong, could easily cause issues / damage the unit.

Are you sure that:

-the correct filter was installed?
-the correct fluid was used?
-the level was set correctly?

 

Sounds like you need a transmission.

 

The whole reason I'm reaching out on here is because these issues are occurring without me driving like a total d*ckhead. If I was just banging off redline and going to takeovers I'd know the root cause of a fried transmission. I drive the car like it's intended to be driven don't get me wrong, but I'm not out here trying to set any public road lap records by any means. Also I did check the pressure in the lines before removing the transmission, and the tune was never put back on after the first initial time I was running it. So with basically all comments being replaced and the tune staying off the car, I'm still racking my brain on why the car won't move.

 

I'm aware there's no torque converter in this transmission, but for some reason everybody refers to it as a torque converter. The shop that did the work, a gentleman at southern hotrod, even my local Mercedes dealership referred to it as a torque converter. I guess they do just to put it in layman's terms because it looks so much like a torque converter??? Seems odd to me as well. Anyways, to answer the rest, the car had to go back because there's been a total of three valve body/conductor plates in the car. The one the car came with, a new one that was replaced during the initial repair, then a third new one was put in when they put the used transmission in. The reason they didn't do the programming is they don't have a star tool so they just did the mechanical work. I'm not going to stick up for this shop because it's apparent they couldn't return a car in working order to me, but they are in fact a pretty renowned shop in my area. They work on cars that are way more exotic and valued far more than mine. I figured if a dude trusts this shop with his aventador then I'd probably be in good hands. I'm just stating this to make you aware that I didn't try to get this fixed at billy bobs backyard repair yard haha. I called around to a lot of trans shops in my area and a lot of them basically hung up the phone immediately because they absolutely refuse to work on anything Mercedes especially AMG. I'm not looking for sympathy, I'm looking for answers.

 

Pretty much spot on except for a couple things.
in 1. The car did not come with the tune, I put it on probably about 8 months into ownership.
in 3. I did all tests I could do while the transmission was in the car before removing it.
in 6. process with shop and dealer repeat + putting a used trans in.
everything else is basically correct

I've heard the opposite about the 722.9 that it and the camshafts/lifters are the achilles heel of the facelift W204

I really can't be sure of the other things like proper fluid level and proper filter because I didn't do it the shop did. I haven't taken the pan off to check filter number. Pretty sure the fluid they put in was blue, with my most recent time draining it it was dirty and almost green. I think the only two colors are red for older years and blue for my year.

 

Ya you are correct on the fluid color. 722.9 is pretty reliable, if maintained and not abused it's pretty robust. Tunes can negatively affect it as many tuners don't modify all the maps you should and the transmission ends up with multiple conflicting shift maps because of this. This cna cause issues with shifts performance or reliability.

 

It seems Gintani or Eurocharged are the top two tunes people usually run. So why doesn't every Gintani tuned C63 eat its transmission? Also why would the same issues come back without the tune on it and all new components?

 

when they replaced the valve body and conductor plates, did they reuse the old solenoids? or did you get 8 brand new ones?

 

They got them directly through Mercedes. So if Mercedes includes them, then yes. If not, then probably not. I don't see them doing this though considering they said they found friction material in the fluid. They originally shipped out the valve body to be cleaned and ordered a new conductor plate. They didn't know that in the newer 722.9's the valve body and conductor plate are married so they had to end up ordering another valve body/conductor plate together.

 

The valve body and conductor plate are not married. The conductor plate and the ecu are married. The solenoids are sold separately and could likely be a culprit for these, somewhat, intermittent issues. I could see them behaving better with new clean fluid and then acting up later when the fluid gets used/dirty. It’s easy enough to replace them if you know how to pull the valve body down. FCPEuro sometimes has the solenoids, I just replaced mine with Rostra brand ones from rock auto. You can test them each electrically and mechanically for proper function, but it’s really not too much money to replace them all. You need 4 blues and 4 blacks.

 

There have been so many incompetent people involved here - which your subsequent posts only further confirm - that you had set yourself up for failure form the beginning.

A jack of all trades is a master of none. The fact that you saw a Lambo in the first shop should have been an indication that they're not the guys that you need to properly service YOUR car. Find a shop with trained Mercedes mechanics. A lot of good and experienced techs leave the dealerships once they hit a certain age to start their own operation or end up going to an independent shop because they're no longer willing (or able) to work at the pace they're expected to work at at the dealership - but they know more about our 10-15 year-old cars than the current batch of new techs at the dealerships will ever learn about them. Someone calling the wet clutch pack a torque converter or not knowing whether the conductor plate is married to the valve body or the ECU is a sign that you need to run away from there. Find a competent local Mercedes expert that only works on Mercedes, and get them to fix and/or replace everything that needs to be fixed and replaced to properly do the entire job. It won't be the cheapest option, but as you are hopefully learning now, you get what you pay for.

People guessing what the issue may or may not be be here based on the information we have is akin to a blind person trying to throw a dart and hit the bull's eye on a dartboard that is inside a moving car 1.3 miles away with the windows closed. It is frankly a waste of everyone's time and energy, including yours.

 

Just got off with my local Benz dealership and they said the solenoids do in fact come with it. I am going to drop the pan remove the valve body/conductor plate and take a look at those solenoids for any debris just to knock off another possible culprit. I will let you know what I find.

 

Yep. And not a scan tool in sight. The basics haven't been performed here so there's no chance of resolution.

 

Imho, do not bother. Take it to the best Merc shop you can find in your area. Look for great reviews and factory trained techs. AMG experience is a plus. The right independent shop is fine. Talk to them and explain the situation. Do not act or talk to them like you think you know anything. Stay out of their way and let them fix your car. Yes, it could be expensive. I deal with a version of this situation every day. Good luck.

 

A replacement oem transmission with 3yr/30k warranty is only like $5k. just do it and never deal with this again. that is the simple solution.

 

Perhaps you could post your neck of the woods and maybe one of the members local to you could point you in the right direction towards someone who has a good track record.

Not to bust your nuts any further but there is no "master mechanic" who can do Lambos, Ferraris, Porsches etc.

Any shops that do this, tend to either be incredibly well staffed with several individuals with decades of experience or are completely full of it, usually the latter.

You don't see a lot of Cardiologists switching to Neurosurgery or vice versa right?

These sales departments are getting really good or the consumer is just grossly unfamiliar and caught with their pants down.

Good luck OP, if you can weather the diatribes from most of these members you will at least get some information to help you figure this out.

 

If it doesn’t move it more than likely is something to do with the drive authorization system which includes the ECU, ezl conductor plate and sometimes shifter. If the conductor plate doesn’t communicate , the car will start but not go into any gear.

 

Yeah, sorry. It was a bit of a diatribe. I'm with what roadtalontsi and GarlicBread said. I hope you get it sorted out.