C63 Guy

Soooo...

First things first, my transmission issues are my fault and not a random failure. That's pretty obvious to me now that I've had the chance to see it disassembled. A couple of the clutch packs were pretty well cooked and the torque converter is done as well. Even if MB had initially warrantied it, I would have had some serious explaining to do when they inspected it back at the mothership. Fortunately, there's little-to-no damage to the gearsets or carriers and I'm getting it rebuilt for a fairly reasonable price. It looks like the main culprit was brakestand burnouts. (That statement would probably be followed by a "DUH!" for most of you, but this is all new territory for me.) Or more specifically allowing the transmission to try to shift during said burnouts. I guess when it tries to shift under load with the brakes applied it really, really, uhm... "warms" the clutches up.

Anyway, now that I've had a chance to see the 722.9's guts, I can say that these transmissions are incredibly well made and, like some members on the forum have said, can probably take a real beating in most situations. Most. The gears are ****ing beautiful, by the way.

As a side note, I got to look at the valve body and see the actual TCU. It's mounted to the inside of the valve body and literally sits immersed in oil, so I'm not sure how tuning it without directly accessing it would work... Changing basic parameters through the ECU, yes, but an actual tune? Yeah, not without making a serious mess, buying several quarts of trans fluid and replacing a lot of torque-to-yield bolts. I'm not trying to start any flamewars with that statement, because there are adjustable transmission variables in the ECU, but calling what some vendors sell "a tune" is a little gratuitous.

So, I'm thinking about ways to beef the trans up and it looks like a better torque converter and clutches are the obvious upgrades. The question is where, who and how do these things happen? Any suggestions are welcome... Thanks.

Josh

Brian GT PRO

Josh..Let's get together on this.

wankeldude

Thanks for the update Josh. One of the reasons why this transmission was never used on the 5.4litre supercharged cars was the fact that it can't handle the torque. Although I'm sure the brakestands didn't help the situation, I wonder if perhaps this tranny is really on the edge of reliability with these tuned NA 6.2's?

Merc63

Lesson: Put tranny in M mode for burn outs.

How many burn outs do you think you did to damage the tranny?

clktoc63

Seems a bit fishy...
We buy these 70k cars, after watching the C63 "Smoke" commercials, and we get stuck paying for a rebuild.

I'd be a bit more pissed, shouldn't a performance car and one that is $70k be capable of a line-lock or two? A lowly GM TH400 or TH350 auto trans pulled from junkyard for $300 bucks could take that treatment all day long for years on end.

Doesn't sit well with me. Given the post, I can't seem to rationalize how "incredibly well made" these tranmissions supposedly are given how well it didn't hold up.

Thanks for the update Josh. My post is NO WAY a dig at your comments, but in your defense.

Kjellster

I would be real interested to hear how many Power breaking burn outs you did as well as I have done a few already but I did it in M mode so hopefully that doesn't damage my trani as much without the upshifting

Please post any and all info you find out about upgrades you get as far as strength and relability improvements goes.

Dads C63

Josh,
SHAME SHAME SHAME on you for doing burn outs.
Why would anyone purchase a performance sedan and abuse it is beyond me. LOL
Keep us updated as to what you find. Sadly enough, I am sure I am right behind you. CRAPP!!

-michael-

Is there any way to retro fit an SL63 or E63 gear box? I mean the one with Dual clutch
As I understand it is the same body as our gear boxes but the inside is different. So theoretically it is possible, right?
But how about ECU, TCU and all the other controlling devices?

Jons95c36amg

The number one killer of trannys is heat. So doing those constant burnouts without cool down boom! there goes your tranny!

LZH

Josh - I hate to say it, but I told you so. With your modifications, increased hp and increased levels of grip, I'm not suprised at all.
And for you guys who think it should be possible to abuse your car and not have it break....well, get a grip. If you beat on stuff, you better be prepared for some heafty repair bills. And remember, the car in question is putting down way more power than it was DESIGNED to have. Added hp + abusive driving = KABOOM.

rantarC63

Don't you want to be absolutely certain that your gearsets and carriers are not damaged before putting this thing back together? If they are in any way damaged, you may find yourself back in the shop before long.

And while your thought about "beefing up" the tranny makes sense, remember that if you upgrade the torque converter and clutches to easily handle the extra power, then the next failure will be somewhere else. You can't upgrade your drivetrain piecemeal without suffering failure after failure until you have upgraded everything that can't handle the extra output. It may very well be that the remaining stock components will handle what you're putting out and your driving style but know you're taking a risk that it won't.

Just my 2 cents.

I do wish you the best of luck and hope this is the last time the Silver Dragon sees the shop for failed components!

yooker

Isn't the only difference the Torque converter is replaced with a Clutch Pack?

Sincity

Sorry to hear this, Josh. I was really hoping it was simply a leaking seal. I wonder how guys like rarfinancial and jrcart are doing with their trans?

Hans Delbruck

Yes I believe so, which likely means burning up clutches even faster.


Am I the only one who feels a "sympathy for the machine" ? I thought it was just instinctual to understand the mechanical limits of a car. Physical limits are fun to explore. But giving the car inputs that will eventually destroy the components/hardware seems counter-intuitive. I don't beat my pets either.

ZephyrAMG

+1. I mean C63 Guy even stated he was at fault, but a machine can only take so much punishment. Why would you do this to such a nice, well engineered, expensive performance car I will not understand...maybe I am missing something here...

Drive to enjoy, not drive to destroy...

-michael-

Because C63 Guy is a true enthusiast!!!

Jons95c36amg

I havent done any burnouts yet. Maybe at the dragstrip.

LZH

That is what you call RACING - when every part of the car is considered consumable and expendable.

callmiro

Man....imagine if you could get a C63 with a 6 spd stick....

Some of these cars would be in the 10's already

Don't get me wrong...i love the paddle shift 7 spd but the biggest preventer of these things being in the 10's all day long is that you can't launch them out of the bucket as hard as you need to.....

If you could do a 4-5 grand launch out of the bucket on a slick or drag radial these modded cars would be running some crazy ET's.....

Hey Josh....when's the Evosport transbrake coming to market

Jons95c36amg

Still not too shabby for a 4door family hauler running 11s with couple boltons. There is got to be a reason why AMG dont make manuals.

brad @ evosport

yes, marketing! they don't believe they can sell them.

The 6-speed SLK320 was an awesome little car. That is the only recent manual I can recall. Of course the cosworth/evo's but they are another era.

MB_Forever

I was just wondering the same thing. This doesn't explain how all the other 7-speed trannies in different cars are holding up so well despite being abused a million times more than what Josh did to his car. The following members, for example, have not had any tranny problems to date:

- jrcart - CLK63 BS - 520 rwhp NA and well over 600 rwhp on NOS (been racing the car all over the country for over two years now. He has done countless long burnouts on very sticky tires and still no problems)

- rarfinancial - CLS63 - 500 rwhp NA and well over 600 rwhp on NOS (been racing the car for almost 3 years. He also has done many burnouts on very sticky tires and this car is much heavier than the C-Class yet he has not had any problems either)

- Juicee63 - CLS63 030 - 445 rwhp and literally thousands of 1/4 mile passes with all kinds of lengthy burnouts on all types of different tires (probably most passes of anyone on the board) and also no problems.

- bryan_benz79 - E63 - 452 rwhp and a few good track days (both 1/4 mile and road course) where he burnt out a few set of tires. No problems....

Thos are the only ones I can think of right now, but I'm sure there are others. Hopefully they'll chime in. Either way I'm glad the issue is being taken care of Josh and hope your beast is up and running as soon as possible.

LZH

It sounds like what you are saying is that burnouts shouldn't have caused this. However, a lot of quick burnouts thru the water at a drag strip is hardly the same as:

Also, most of the racing Jrcart has done has been on road courses where the car was designed to perform.
Point is guys....when you modify your car and beat the crap out of it, you have to assume that something is going to break and you are going to pay for it. I wonder if the dealer would cover this under warranty if it happened to someone with a bone stock C63 ?

callmiro

Holy broken record....we get it.....

Thanks for the lecture dad...and i promise to never ever do it again....

that reminds me of other things my dad says like...

"Here’s a strawberry, sorry for farting near you…Hey! Either take the strawberry and stop bi+ching, or no strawberry, that’s the deal."

http://****mydadsays.tumblr.com/

mkonei

hooley just had some feedback on a rebuild from renntech, maybe he would have some info for you. Southern Hotrod used to post under "builderbill" as well, and i think they had a decent reputation. try to pm blackonblackclk or blackbenzz, they might have had some work done through them. i know you dont have the 722.6, but its worth a shot