Mercedes SLK World banner

1 - 7 of 7 Posts

·
Registered
Joined
·
17 Posts
Discussion Starter #1
Hi!

In november I got my 55AMG and I love it. I sold my SLK 200… :)

BUT!

The car was cheap couse gearbox (7g tronic 722.9) was damaged. The transmission tugged but in strange way. The gears changed smoothly and from the beginning I thought that the problem is in the clutch and not in the gearbox. I wanted to solve the problem. Unfortunately - the mechanic wanted to cheat on me, he said gearbox is destroyed, so i swapped it and I stayed withe the problem. When I changed the mechanic which is unfortunately very far away, he solved the problem. In the settlement, he accepted my old gearbox, which was in parts. He said that my original gearbox was in perfect condition and made no sense to change it :(. The problem lies in the clutch. He swapped the torque converter and put one from S500. He solved the problem! :grin: During going back home from mechanic (about 400km) when I pushed full gas, and 3 gear, sometimes at 2 gear the the clutch suddenly pulled off the connection.:frown: This situation was repeated sometimes for about a month. Suddenly, something broke down. When I drive smoothly, everything is ok. When i push gas stronger - the drive system is disconnecting, the car is not going, only engine speed is incerasing. Than, gearbox put 5th gear and it is the only possible gear till I turn off the engine and start it again. Sometimes, even when I drive smoothly, the drive system can disconnect. It looks like the power of the car was to much for it. I'm not sure but the car is modified probably. The seller said the SLK was modified for 420 horsepower. Anybody has any ideas? This fault is different from the last one when the transmission tugged. To strong car destroyed another clutch? Is it possible to mount stronger torque converter from SL55 AMG with 500 horsepower? Does this part fit?
 

·
Registered
Joined
·
463 Posts
When you say "clutch" my guess is you are referring to the lock up of the torque converter since '55's transmissions are automatic shift and don't have clutches in the traditional sense of the word (you don't need to row your way thru the gears from first to 6th).


Are you saying the transmission is slipping when you press on the gas, as if the motor rpm rises but the vehicles speed doesn't really change?


By the way, if it puts your mind at ease at all, with under 500 hp at the wheels, there is virtually no way your engine has enough power to trash your tranny or torque converter.
 

·
Registered 2005 SLK55 AMG & 2006 Kleemann 55K S8
Joined
·
921 Posts
Your torque converter is not locking up any more, it is staying unlocked.
 

·
Registered
Joined
·
17 Posts
Discussion Starter #4
Thanks for replies. So, are you sure those components are quite strong and should manage 420hp?

I said clutch - I know in the car is torque converter, not clutch exactly, but in Poland at torque converter we say "hydrokinetic clutch", but if it is misleading, I'll use torque converter word. Of cousre I have quite a lot of knowlege about how TC, transmission works, I repair lots things by my hands, my father is an mechanic. :)

Yes, exactly - the transmission is slipping when I press on the gas, as if the motor rpm rises but the vehicles speed doesn't really change. It looks as if I press a clutch in a car with a manual transmission. When I add gas - the car does not accelerate. When I take my foot off the gas - the motor rpm drops. After that, the gearbox put the 5th gear and it's the only possible gear which works till I turn off the engine and start it again. What is strage - when the car is cold, the 1st and 2sd gears works correctly. The problem appears on 3rd gear. (but sometimes on cold engine everything works perfect on every 7 gears! :O) When engine is hot, the problem appears ond 1st and 2nd gear too… Looks exactly like if i had press the clutch pedal in car with manual gearbox and press on the gas - the car is not moving. ... I will try to replace torque converter, should it help? I was wondering, maybe there's something wrong with oil pump? I don't know. It's the middle of the summer and my lovely car doesn't work :(
 

·
Premium member 2009 SLK55 AMG
Joined
·
4,926 Posts
Could this be a conductor plate issue? The symptom of the car sticking to one gear, until the engine is turned off and restarted sounds like the typical conductor plate / speed sensor problem...
 

·
Premium Member 1999 SLK 5.4 M113
Joined
·
1,438 Posts
Sounds like a conductor plate to me as well. did all the codes get cleared out of the TCU?

could still be in limp-home mode.
 
1 - 7 of 7 Posts
Top