Clutch relearn/Gearbox reset - E63 W212

[FateSynchro]

My box is a bit less smooth first thing on a morning and sometimes after been stood (hot) for a few hours, usually 2nd to 3rd and 4th to 5th are the two that make a more obvious shift, its not mega rough or anything but there is a noticeable difference between the rest of the shifts.

I have changed the oil/filter twice already so its not that, level is correct... is there any way you can reset the gearbox learning pattern, or do some form of "clutch relearn"
On my GTR if you were getting rough shifts you could do a clutch learn which would adjust clutches so any wear was taken up and shifts were smooth.

can we do anything like this?

 

[longman h]

Here you go mate;
http://www.mercedesmedic.com/reset-mercedes-benz-transmission-procedure-instructions/


Sent from my iPad using Tapatalk

 

[FateSynchro]

Thats just for the shift points, i've tried that one already, didnt work.

 

[RJ C63]

In my car c63 is seemed to forget all the gearbox adaptations after 5 days of no use.

 

[daveenty]

Adaptations can be done by either driving it whist connected to star and setting the values or, as recommended to me by me dealer, just by driving it.

I put mine on star and set it to "unlearn" what was there already, then just drove round for a few hundred miles, though the kick down is still a bit hit or miss.

I don't know if you're aware, these boxes will only learn in S or S+, not C.

 

[FateSynchro]

Adaptations can be done by either driving it whist connected to star and setting the values or, as recommended to me by me dealer, just by driving it.

I put mine on star and set it to "unlearn" what was there already, then just drove round for a few hundred miles, though the kick down is still a bit hit or miss.

I don't know if you're aware, these boxes will only learn in S or S+, not C.

Yeah i knew that, its why i'm after a actual Clutch relearn not just a shift point adaption.
The box is smooth 95% of the time, but when its cold 2nd to 3rd and 4th to 5th you can "feel" rather than the other gears which are totally smooth.

 

[AlexM]

Hi,

I have this issue also. My car seems to slip or surge between 2nd and 3rd when cold. I've been told that it's characteristic of the car, but did think I was being fobbed off. It is much more pronounced when it is a low ambient temp (i.e. during the british summer!).

If the problems are when cold, I don't think there is much that can be done from Star to fix that. I think the shift adapations are fill time adaptation (for the relevent actuator) and line pressure adaptation are the parameters that control the clutch actuation, and these can be adjusted at those three ranges only for upshifts and downshifts.

From reading the Star adaption process, there are three adaption points - gearbox oil at 60, 90 and 110 degrees. It seems 60 deg is the lower threshold for carrying out adaption operations, so it doesn't really help with cold operation. To note also, I believe this is supposed to be done after an oil change, presumably to account for the change in lubricant properties - was this done?.

I've decicded not to worry that something 'bad' is happening.. more that the oil is cold when thick and it causes the clutches to engage more slowly. I can drive around the problem by throttling off when the gearbox shifts, and wait until it has warmed slightly before giving it too much throttle. It seems worse in 'C' mode than 'S' or 'S+' - do you notice the same?. What fluid is specified for the MCT 722.9?. Are there multiple suppliers?. Cold viscosity might be something that varies between oils - if the viscosity was more similar between cold and 60 deg, would the shifting be more consistent?.

See 722.9 workshop tips and tricks PDF below for more info:

www.askatech.com/askatechlive/forums/resourcehandler.ashx?a=4552

Cheers,
Alex

 

[Bryan Allman]

I think its software related to throttle position. If I use very light throttle (eighth to a quarter of an inch), the car will jump shifting between 2nd & 3rd in C mode. If I increase the throttle to half inch or greater, no jumps and very smooth changes throughout.

As has been mentioned earlier, no jumps in S or S+ mode on light throttle

 

[FateSynchro]

Hi,

I have this issue also. My car seems to slip or surge between 2nd and 3rd when cold. I've been told that it's characteristic of the car, but did think I was being fobbed off. It is much more pronounced when it is a low ambient temp (i.e. during the british summer!).

If the problems are when cold, I don't think there is much that can be done from Star to fix that. I think the shift adapations are fill time adaptation (for the relevent actuator) and line pressure adaptation are the parameters that control the clutch actuation, and these can be adjusted at those three ranges only for upshifts and downshifts.

From reading the Star adaption process, there are three adaption points - gearbox oil at 60, 90 and 110 degrees. It seems 60 deg is the lower threshold for carrying out adaption operations, so it doesn't really help with cold operation. To note also, I believe this is supposed to be done after an oil change, presumably to account for the change in lubricant properties - was this done?.

I've decicded not to worry that something 'bad' is happening.. more that the oil is cold when thick and it causes the clutches to engage more slowly. I can drive around the problem by throttling off when the gearbox shifts, and wait until it has warmed slightly before giving it too much throttle. It seems worse in 'C' mode than 'S' or 'S+' - do you notice the same?. What fluid is specified for the MCT 722.9?. Are there multiple suppliers?. Cold viscosity might be something that varies between oils - if the viscosity was more similar between cold and 60 deg, would the shifting be more consistent?.

See 722.9 workshop tips and tricks PDF below for more info:

www.askatech.com/askatechlive/forums/resourcehandler.ashx?a=4552

Cheers,
Alex

Great post Alex, thats exactly what i want to see, i have the exact same you desribe right down to the more prounced in C than in s and s+ although i never use those modes when its cold.
I have also noticed that if the car is throttled hard in s+ mode you get a snappy gearchange (charactistics of the mode yes i know) but for everyone having to reign back torque to prevent this issue when mapped, if you drive hard in C mode gear changes are smoother, the Snap is a design feature to make you feel like your changing gear like a manual car... that thudding gives the impression of brutal acceltration.
And it works well, however the time gap needs to be smoothed out when running more power, lower line pressure for longer rather than a quick burst of high pressure.
you'd still get the snap it just wouldnt be as obvious...

Anyway, if we could find some more specs on the fluid we could look into running different oils.
Any ideas? i might speak to Opie about it, do we have the exact gearbox code?
I got this back from Tim last time i spoke


I have 2 oils listed for the gearbox, but I'm not sure which one you need

Fuchs Titan ATF 4134 for Mercedes - meets MB 236.14
Fuchs Titan ATF 7134 FE Low Vis Mercedes 7G Tronic Plus

One database lists it as needing MB236.14 (ATF 4134), another as 236.15 (ATF 7134), but I do not know which one is definitely correct. I have 2 gearbox codes listed, 722.931 needs the 7134, 722.971 needs the 4134.

Your diff takes a 75w-140 LSD oil and the Castrol Syntrax Limited Slip, Gulf Gear LS, Red Line 75w-140 GL5, Fuchs Sintopoid LS, Motul Gear Competition and Millers CRX NT LS are good options.

75w-140 Gear Oil For Manual Gearboxes

Also to answer your questions, no i did not reset the gearbox after changing the oil i merely disconnected the batteries for 30mins and reconnected everything was sublime after that, but the gearbox has picked up this bad habbit of shifting sloppy to 3rd when cold, but i can 100% say that it was not there after intial cold start after the TCU was reset.

 

[FateSynchro]

I think its software related to throttle position. If I use very light throttle (eighth to a quarter of an inch), the car will jump shifting between 2nd & 3rd in C mode. If I increase the throttle to half inch or greater, no jumps and very smooth changes throughout.

As has been mentioned earlier, no jumps in S or S+ mode on light throttle

Just seen this in my reply.. yes its very odd isnt it... i have the latest TCU software.. maybe no one has made MB aware of it so it was never "patched"

 

[AlexM]

Which oil did you use when it you changed it?

 

[FateSynchro]

Which oil did you use when it you changed it?

Factory blue OEM merc oil from my dealer.