[BenjaminSimon]

I am having some concerns regard the transmission. My CL is still under warranty. I have a question regarding what is normal operation with a 7 Speed Transmission.
The issue has been address a few weeks ago. The problem was whenever the car is decelerating, right before coming to a complete stop, the car would jerk. This would occur every other stop. The jerk was very noticeable.
The dealer updated the software on the transmission. Furthermore, the transmission fluid was ½ quart low, and it was topped off. Oddly enough, they could not find any leaks. I am not really sure how that happens.
Now the jerk occurs about every 1 out of 5 stops. The jerk is not as serve, but it still very noticeable.
My question is, is this normal? If not, and someone else has experienced this, what was the solution?
Thanks in advance!

 

[guv]

I am having some concerns regard the transmission. My CL is still under warranty. I have a question regarding what is normal operation with a 7 Speed Transmission.
The issue has been address a few weeks ago. The problem was whenever the car is decelerating, right before coming to a complete stop, the car would jerk. This would occur every other stop. The jerk was very noticeable.
The dealer updated the software on the transmission. Furthermore, the transmission fluid was ½ quart low, and it was topped off. Oddly enough, they could not find any leaks. I am not really sure how that happens.
Now the jerk occurs about every 1 out of 5 stops. The jerk is not as serve, but it still very noticeable.
My question is, is this normal? If not, and someone else has experienced this, what was the solution?
Thanks in advance!

Have you just purchased the car? if so possibly still adapting to your driving style, if not try changing the gears manually to see if the same problem occurs, unfortuantly will autoboxes you can get the problem you say about even on new cars, normally a bang or a thump changing gear is normally low fluid or worn box, anything else is normally electronic/driving related. sometimes a good autobox additive will help

 

[msbarsi]

Hi BenjaminSimon does it happen in comfort or sport position? In sport the gearbox should downshift automatically when you brake or decelerate but a jerk seems unlikely to me. As guv said probably the car is adjusting to your driving style since these boxes are adaptive so they take some time to learn our style. The 7G-Tronic doesn't have a sick to check the fluids level but since your box was missing 1/2 quart I'd suggest a complete gearbox fluid replacement together with the gearbox filters and a reset/update of the gearbox software so you and the car can star from scratch and sort of growing up together like a married couple if you see what I mean.
After a while I purchase mine (2003 CL 500 NAG-II 5 speed 'box) the box was missing more than a liter and when accelerating had sometimes the car went to neutral and I had to restart the car to reset the box. The dealership found the liquid was missing (no leaks of any sort) and after topping the problem disappeared. They also suggested a complete fluid and filters replacement as soon as I felt like and after a few weeks I (them) did it. They told me the old liquid was brown against the new blood red and since they are close friends of mine there I have no reason not to believe them on the subject so I guess it's time to have a look at your liquid for your car.

Hope it helps.

Cheers.

 

[LondonThing]

what throttle opening are you on? Possibly this is a drive by wire problem where you're not quite closing down to zero throttle and the signals are confused. I can just about get an occasional thud out of 7Gtronic, in Sports mode, on very light throttle, when the car is warm verging on hot.

 

[Marsden]

This has been known to happen with the 7-spd tranny. I've had two of them and experienced it with both. Have taken them into the dealer and had software updates, etc. (as you did), and sometimes it just moves the clunk around--that is, it then occurs under slightly different conditions, but usually less often.

Fortunately the symptom is intermittent and not terribly bothersome to me. But my experience is the same as yours; the updates did seem to help a bit, but did not provide a total solution. I've just elected to live with it, and since my CL is used mostly for highway trips, I haven't been motivated to pursue it any further.

 

[Chauss]

I had the same symptoms on my car.
Check the electronic switch on the side of your transmission....the O-rings go bad. Good place for an electronic switch-eh? If there is fluid on the wires the O-rings have gone bad- must replace the whole switch, luckily not too expensive...this is a known problem on the 5 speed cars- perhaps it is on 7 speed also?

Transmission Gasket/Bushing/O-Ring; Adapter Plug with O-Rings
Transmission cable adapter plug to connector plate, o-rings no longer available separately must replace entire plug. Recommended replacement with filter and fluid change per Mercedes. For models with 722.6xx electronic 5-speed automatic transmission. 1 per car.

 

[BenjaminSimon]

Thanks everyone for the replies.
I purchased the car 6 months ago, so I doubt it is still "learning".
This occurrence happens on S as often as C.
When the dealer told me the fluid was low .5 quarts, I asked if it appeared to be leaking anywhere, and they insisted no.
Nevertheless, I am taking it back to the dealer April 8th. That is the first day I can get a loaner. I will let everyone know the solution.

 

[BenjaminSimon]

The dealership had the car all week, and finally called me today and they could not find a problem. In fact, after a few drives, no one could "feel" the problem. I am going there Monday morning to drive around with them.
I suppose I wanted to confirm this is not a normal characteristic of the 7 speed. I would be shocked is it was normal.
Perhaps it merely needs a fluid flush. IDK.

 

[hatemycl]

Just bumped into this thread. You probably have bad solenoid(s) in the transmission. And it should say that in the hand held diagnoster tool. That jerkiness is that and dont let anyone tell you otherwise dont waste your time on a transmission mount either (and had you done so, you would only feel a harder jerk), i also changed the driveshaft couplings and boy did the jerkiness just get worse.

Try this, let them reset the tranny solenoid faults, go for a spin (go gentle on the acceleration/decceleration) and you will notice its okay? give it a few days (or harder acceleration/decceleration) and the issue will repeat once again.

I just tried to search for this problem, hoping to find which solenoid I need, and found your thread. My tranny comes with 6 solenoids, 4 of which are listed under mercedes part name "solenoid valve" and the other 2 listed as "pressure control valve".

Hope you can help telling me which solenoid you ended up buying! I dont want to buy all 6 of them but I might do that and save labor time

 

[BenjaminSimon]

Hi, thanks for the follow up. I was never able to fix it the problem. My "jerk" only occurs every 1 out of 15 times, so I have just accepted it.

 

[hatemycl]

any chance you have a copy of the mercedes fault report?

My mechanic's printer gave up right after we got the report.
Will reply to you once I get it from him.

P.S. I know the giving up feeling. I must admit, my CL 600 made me earn a PHD in mechanics lol.

 

[hatemycl]

after:

1- a good 2 years of my transmission jerking around
2- tranny fluid and filter change
3- fault reset
4- resetting "adaptive" tranny learning whatever

.. things just got more jerky. Not only does it jerk when slowing down at a stop light, but even when cruising. So damn annoying and scary too. Gives me a feeling the tranny could lock in gear and not shift.

So, :surrender: I decided I'd surrender to the 6 solenoids purchase but the guy at the parts counter stopped me! Said they never replaced any solenoids before and that there is a commonly sold 'transmission kit' that I should try changing first. Its called an "electrics kit" under mercedes parts name. Its the freaking motherboard that all 6 solenoids are connected to. And it costs the price of one noid so I'll try that first. Maybe its just zapping my noids erratically? i dunno but im finding out.

Parts sales guy says he sells these VERY frequently, and that under the mercedes scan tool, it will only report a bad solenoid and does not report bad "electrics kits" (even when the kits are the issue).

wish me luck.

 

[hatemycl]

This could help:

http://www.benzworld.org/forums/w21...ission-control-module-99-e-6.html#post3538903