Pekkle

Guys please give me any insights if possible. My car awhile back during breaking at the stop sign gives me a strong jerking motion that felt like some one rear ended you. Most recently I felt the same thing repeately, but this time I am at bumper to bumper traffic, I would say about 5-15 miles speed. I took it to the dealer and they duplicated the issue and said they would replace the value body. However when they called me all they said was they updated my transmission software. But I have to say right after they updated the software my transmission does shift rather smoothly, even in the morning when my transmission thend to shift rough for the first two times. But after about a week now, my transmission starts to shift rough during morning again, so I am thinking when they did the software update, they must have reset the transmission that's why it's shifting smoothly? So far I don't have bumper to bumper traffic again, so I can't tell if my transmission is going to jerk or not, but can this be normal? and can this be cured by a software update? I have about 700miles left to 50,000 miles so I really need this thing to be fixed..

lowcabbie

do a glycol test, u may have radiator fluid in your tranny

gaazmon

highly doubt it's glycol, his car is an 07. that thing stoppped after MY 04.

sounds like bad 2 > 1 shift. common on these 7 speed trannys. could be the valve body.

imagine, for the MY 2010 cars, MB puts the software so that when you start the car, the tranny defaults to C because so many people complained of the 2 > 1 shift and they couldn't fix it

Pekkle

Thanks for the reply, is this a common issue? what are the cost to do a glycol test?

220S

Ha, that's very possible they did that to the W212. They can't fix the MCT either and so in the new W212 E63 it's jerky just like the SLs.

And yeah, to the OP, Gaazmon's right the glycol issue won't/shouldn't happen in your 2007. The radiator vendors were changed. The valve body was the culprit in the 7-G tronics. Lean on the dealer more and try to get a VB replacement.

charliele729

A lil jerkyness I find is common, especially during a downshift like during braking where the break assist would kick in using the engine rev for extra breaking power. I do have to agree that the S mode starting from 1st geat is not as smooth, But definitely smooth as butter when it is in Cmode. I just stick to C mode, shift alot smoother for me and besides if you punch on gas even in Cmode, it still starts out on 1st gear.

gaazmon

yup, instead of fix the problem just mask it i guess

ya i've heard about the problems with the MCT

charliele729

My 1-2nd shift in S mode, seems pretty smooth, but there are times where it is a bit jerky. Definitely not harsh like someone rear ended me though. The 7-G tanny is by far sooooothest than any tranny I experience with.

Barry45RPM

Its the 2> 1 shift that is the problem. Its a common problem with these transmissions since they were introduced in 2004. Most of them do it... some never do. Usually a valve body replacement and new software can solve the problem... in some cases forever, in other cases temporarily. The more they play with it, the more likely you will end up with Franken-transmission. I'm surprised that MB didn't default the start-up software to default to the "C" mode at start up by now. That's the for sure cure.

Lean on your dealer for a cure, MB really doesn't have a 100% cure for this so they don't like throwing money at it. In time you'll get used to it anyway.

gaazmon

man, i had a 2010 GLK350 as a loaner once and EVERYTIME it went from 2 > 1 the thing just threw me back.

220S

They need to put the new DCT in all AMGs, not just the SLS. MCT is kinda funky especially in traffic.

p.s., where have you been? They don't have internet access in jail? LOL.

Pekkle

Thanks for all the inputs. But I forgot to mention, the jerkness that I felt actually was in the C mode. and only happends during bumper to bumper traffic. So I am not sure if this involves the 1st gear though. I am actually suprised that no one experienced the problem like I did, which is rather scary because you look at the back of the mirror only to find out that the car behind you is at least 3 car length away from you. I will need to take it back to the dealer again and see what they are going to do, but most likly they will have their foreman test drive with me again, and they may or may not feel it that's what sucks about this. If they can't feel it, they don't want to help me.

BTW, if the problem doesn't get fixed will this damage my transmission in the long run? Because this seems to me has gotten worse and worse over time.

gaazmon

LOL . oh man i knew someone would mention me being gone. ya, they sent me to some place on some island in the Caribbean or something, the place started with a G i think

nah, i was away at a camp i do volunteer work for 1 week out of the summer up in the mountains. and then there was some virus that got around the place and about 30% of us up there got it so i was sick for like a week when i got back. it's good to be back on the boards

gaazmon

oh, is it like a rocking motion at around 5 mph? i have the same problem (5 speed) in traffic. they were never able to fix it

eddieo45

I had the same issue in my CLK and posted about it HERE. Brought it to dealer before warranty was up and a long list of screws, seals and rings got replaced, and, per repair receipt: "B1 and B3 clips had popped out; remove and replace clip and spring on B3 assembly, remove and replace B1 assembly with K1 replacement per DTB P B 27.60/92".

Pekkle

After the repair, do you ever experienced that again? I wonder if I can bring your post to dealer and see what they will say?

eddieo45

I'm good since then. PM me your email and I'll send you a PDF of my WO from dealership. Heaven knows what it'll cost later!

BagMan

I just picked my car up after getting this fixed. SA says they replaced a snap-ring. Car seems to be good now.

About two weeks ago, I noticed the 2-1 shift became noticably harsh. My SA noticed it too when I was in for service and offered to take care of it under CPO warranty.

He said it would only get worse with time if ignored.

eddieo45

Sorry it took me so long to scan and post this. See attached for the laundry list of clips, screws, and other parts they replaced to fix this condition.

jerome8283

I have an '07 350 sport and have the same problem. I've been to the dealer a few times about this and they were not able to fix this. The problem was two fold, when downshifting from 2 to 1 it is harse and just before coming to a complete standstill I would feel a slight bump as if someone tapped me from behind. I supposedly had the valve assemble replaced but no difference. I do not recall the SNAP RING being replaced though.

I did notice an adjustment made by the dealer though. Now when I come to a complete stop the MPG does not display 0 immediately. I come to a complete stop and the MPG is slightly behind showing 1 then 0. I think they did this to cover up the slight bump I feel just before stopping because this no longer occurs. But downshifting from 2 to 1 is still harse. It's a little better when set to C (comfort) instead of S (sport).

I read somewhere that the newer models still have this problem and Mercedes automatically sets S (sport) to C (comfort) once the car is started.

djrabbi

same problem with mine....but i have 03....i did the glycol test and came back negative....got a dianostic done at MB and tranny is shot completely.....

jerome8283

What is the glycol test?

mcleantmw

A test to determine whether you have coolant contaminating your transmission fluid.......a real killer for torque converters and transmissions.

werewolf34

Don't worry, it's not like Ebola is contagious or anything....lol