7G Tronic gearbox faults

st4

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I have a harsh shift from 1 to 2 when the car is cold. Updates, reset adapations have not solved the issue. I have to live with it.

Shame as the engine is a belter, but the gear box is a bit ****
 

jimsinessex

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I have read this a few times, but my 7g doesn't roll back on hills in S or C, it doesn't feel as though it goes into neutral either:confused:

Neither does my 7G, the idea of it automatically selecting neutral at every stop sounds like the fastest way to wear out the 1st gear clutch pack.

Jim
 

drdre78

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hi that not true.7G gearbox when it came out on CLS they where replacing them due them breaking clip in box.alot of complaints about unsmooth gear changes.but it has got alot better since gearbocx software updates.As of 2010 there is new 7g gearbox fitted to all new mercs.you can tell by sump
 
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moosehead

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Despite numerous updates, new valve pack, etc. to sort our the clunky gear changes, mine still does funny things from time to time. It has never held on a slight incline (forward or reverse) even with the new valve pack or s/w updates. This has been described as a 'feature' the few times I mentioned it.

I've come to the conclusion that 7G boxes all seem to have different characteristics and if you are lucky you might get a good one. Back in the summer when my Indie was changing the brakes he did mention that a modified sump had been fitted to my box. I can only assume that this was when they changed the valve pack. Very mysterious!
 

mikestrivens

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Seems like MBs have got unnecessarily too complicated for their own good.
 

kamalpatel12448

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Folks, wanted to update you on this issue we discussed....

I finally took the car into MB Brooklands and they updated both car and transmission software, they went for a road test and checked data being provided. Not tested from cold start as I didn't leave it with them overnight. They said that there are readings/tolerances of up to ±20 and mine were reading ±2 so they were very happy with it. I think that MB were a bit nervous as I asked a lot of questions and I wanted the work done while I waited (free wi-fi and tea provided) so I worked in the nice surroundings of Brooklands for the morning, but very happy with the service I got that day. Another reason why I took it to Brooklands is because they probably have more AMG's coming through the workshop than others, so one can hope they are quicker in getting to the solution.

I've now been driving it for a week in sport mode and the gear changing is much
smoother all round, now going to drive around in comfort mode for a few days and revert back to sport to verify behaviour. The results so far are very good, no hard change downs across any down-shifts.

I know the box will be learning for a while (the way I drive) and not sure how long that goes on for but if you have a C63 and have a 2-1 hard down-shift I would suggest getting the latest software put on it.

Will update on this if the situation changes for the worse and any action taken.

Thanks for the advice to all and all the replies.

Kamal
 

padesu

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Just recently aquired a 2007 w203 c320 estate with 54k and experiencing some problems with the box.When cold it's very reluctant to change out of first unless I upshift manually also when it comes to stop it jolts as though I have stepped hard on brakes-only happens once then ok for the rest of the day.I have been using it in s mode but seems to have a mind of it's own and changes up and down not always when I would expect which makes for a jolting journey at times!
It also on occasions sticks in 3rd despite attempts to manually upshift will not respond and only sorts out if I downshift to 2nd then upshift ,ok after that,seems like possible software problems?? haven't run it into mercedes yet and don't know what the history is in relation to updates carried out to it up to now (are these done as a matter of course or only when complaining ?)
If anyone has any ideas I would love to hear.
 

M80

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I've done a few K miles in the C320 7g.

It can be a bit clunky when slowing in the lower gears, but not as bad as I have read here.
A couple of times after many miles (definitely well warmed) just won't go to 7th, even 80+ on the m'way it just won't go. Maybe 20 miles later ?? it has.
There is a reluctance to kick down, it'll tip ok but in auto it has to think a bit. To be honest I thought maybe I had trained it to enjoy higher gears and has become lazy.

I can't feel any difference between C and S.

I'd like to see it happy in top at 50 instead of 57ish, it's a common speed limit nowadays.

I can't describe the 7g as always seamless, not like the 5g, but then this one pulls away in 1st in Comfort and that's better.
 

ALFIEBEARD

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My opinion of the 7G is that it changes seamlessly! and only shows a harsh-ish change down to 2nd when really cold (ie within a mile of cold start) in the winter, but only when in C mode its fine in S mode.

My car is a 56 plate CLS 320 CDI and has covered 70k, I wonder if the problems I keep reading about on here, are because the Autobox is learning a driving style that promotes hard downshifts and late upshifts etc.

I drive 1 ml on an A road then 23mls on motorways every day, my car doesn't go into 7th until 60mph, and when in C (comfort) starts off in 2nd gear, also my car never rolls back when in drive.

I am either very lucky with my Autobox or the last owner got it sorted prior to my ownership, there is no history of any software!, or repairs carried out on my car previously though, apart from an oil change at 48k.

Alfie
 

television

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My opinion of the 7G is that it changes seamlessly! and only shows a harsh-ish change down to 2nd when really cold (ie within a mile of cold start) in the winter, but only when in C mode its fine in S mode.

My car is a 56 plate CLS 320 CDI and has covered 70k, I wonder if the problems I keep reading about on here, are because the Autobox is learning a driving style that promotes hard downshifts and late upshifts etc.

I drive 1 ml on an A road then 23mls on motorways every day, my car doesn't go into 7th until 60mph, and when in C (comfort) starts off in 2nd gear, also my car never rolls back when in drive.

I am either very lucky with my Autobox or the last owner got it sorted prior to my ownership, there is no history of any software!, or repairs carried out on my car previously though, apart from an oil change at 48k.

Alfie

It was the earlier ones that had all of the problems with hard shifts, yours should be OK
 

RANA_1

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Hi,

Not sure how beneficial this is but was asked to drive mine at 60mph for min 15 minutes to clean up the EGR and this should be done on a regular basis because my daily journey is not a long run.
 


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