torque convertor lock up

[Glenn Smith]

I was just reading the post on the Valeo radiator issue, i see that in the diagnosis they refer to disabling the torque convertor lock up clutch, my c230k (202) has the 722 6 transmission with tip shift, but does not appear to have a lock up clutch, is this correct i wonder? did some have it and some not, i haven't seen any reference to it in the drivers manual either, i never feel it engage, i would assume it only operates in top gear above a certain speed as my jag does (around 53mph) and is quite noticeable when you accelerate that the drive is then direct.

 

[television]

Glen, the Valeo issue does not affect the 202 car,its the 203 that is affected

There are 10 versions of the 722.6 gearbox

 

[Glenn Smith]

Glen, the Valeo issue does not affect the 202 car,its the 203 that is affected

There are 10 versions of the 722.6 gearbox

Yes understand my car should not be affected, (although i say any auto with the oil running through the radiator could be affected) just wandered about the lock up clutch as i had not noticed one on mine.

 

[BlackC55]

You do have one.

 

[Glenn Smith]

You do have one.

I do? I don't think it works then, what sort of speed does it lock up at? Wouldn't i feel it lock up and notice the drive being direct rather than torque converted (if you know what i mean)? i just assumed it didn't have one as it doesn't appear to lock up and no mention in handbook. any other auto i've driven i can always tell when the converter has locked, often feeling it as it does so.

 

[television]

They lock around 50mph but this does depend on the car, as there are many versions, my box is so smooth I could never tell when its locked up

 

[Glenn Smith]

They lock around 50mph but this does depend on the car, as there are many versions, my box is so smooth I could never tell when its locked up

I can't see how you can't tell, if you accelerate even gently the torque converter will giving some slip, as the lock up occurs the slip dissapears, any accelerating beyond that speed and in top gear there will be no slip, in my jag it is really very easy to tell, lock up during gentle accellerating is similar to a gear change, from then on (unless the box changes down) it is easy to detect the more direct drive (ie no slip caused by torque conversion) is the Mercedes lock up working in a different way, as mine certainly isn't locked even at high speed (can tell when you accellerate, as you get the torque conversion) Any one else with a c230k? is yours the same? do they actually have a lock up? and when does it work?

 

[television]

I can't see how you can't tell, if you accelerate even gently the torque converter will giving some slip, as the lock up occurs the slip dissapears, any accelerating beyond that speed and in top gear there will be no slip, in my jag it is really very easy to tell, lock up during gentle accellerating is similar to a gear change, from then on (unless the box changes down) it is easy to detect the more direct drive (ie no slip caused by torque conversion) is the Mercedes lock up working in a different way, as mine certainly isn't locked even at high speed (can tell when you accellerate, as you get the torque conversion) Any one else with a c230k? is yours the same? do they actually have a lock up? and when does it work?

Ok I understand now the problem and I know what you mean.

I do have the list of speeds, later in the day I will have a look for the 202 C230k

 

[Rory]

I agree with the above - if my W203 C270CDi has lock up then I can't tell. And even gentle accellerating at 70MPH on the motorway has the revs rising ahead of the speed increase.

Other manufacturers make a feature out of lock up (some can lock-up in every hear), but I've never seen it mentioned by MB themselves.

 

[Bazzle]

AFAIK they dont normally always completely lock up from what Ive read.
There is a graph produced by MB that shows the conditions of degree of lock. I cant locate it. will keep searching.

Bazzle

 

[television]

AFAIK they dont normally always completely lock up from what Ive read.
There is a graph produced by MB that shows the conditions of degree of lock. I cant locate it. will keep searching.

Bazzle

Was it not on the older cars,with early 722.6 boxes where lock up could be felt, as I said there are 10 versions of this box, and no too models do the same thing or behave in the same way, I believe that I have that graph somewhere, I will look too for it,though I do have the figures for the individual cars, but that is an eve job

 

[Rory]

Ah - perhaps this explains what's going on:
http://mbclub.co.uk/forums/showpost.php?p=20183&postcount=9

 

[television]

Ah - perhaps this explains what's going on:
http://mbclub.co.uk/forums/showpost.php?p=20183&postcount=9

Thank you young man for coming to the rescue.

 

[Glenn Smith]

Ah - perhaps this explains what's going on:
http://mbclub.co.uk/forums/showpost.php?p=20183&postcount=9

Ahh, very good, like a variable rate torque conversion, so would the lock up occur whilst on the over run to give more engine braking? Thanks, i was begining to get concerned i had a gearbox fault-not that i would have worried too much as it has always been the same.

 

[Rory]

Ahh, very good, like a variable rate torque conversion, so would the lock up occur whilst on the over run to give more engine braking? Thanks, i was begining to get concerned i had a gearbox fault-not that i would have worried too much as it has always been the same.

While I was Googling I did see comment about lock-up helping engine braking but that was related to auto trucks (in the US). I don't know any details about how the lock-up works - perhaps someone that does could enlighten us?

I have to say that the concept in Dieselman's post that I linked to of "slipping" lock (and I came across that term for other auto-boxes too while Googling) seems something of an oxymoron.

 

[Bobby Dazzler]

Lock up is only detectable during gentle acceleration at low speeds in my C32 - around 1500rpm. It took me a while to work out what it was.

 

[television]

While I was Googling I did see comment about lock-up helping engine braking but that was related to auto trucks (in the US). I don't know any details about how the lock-up works - perhaps someone that does could enlighten us?

I have to say that the concept in Dieselman's post that I linked to of "slipping" lock (and I came across that term for other auto-boxes too while Googling) seems something of an oxymoron.

Lock up effectively does what it says on the tin, it means that the flywheel is locked up to the diff, with no variable factor in between just like a manual in top.

 

[Rory]

Lock up effectively does what it says on the tin, it means that the flywheel is locked up to the diff, with no variable factor in between just like a manual in top.

Well... Dieselman's post that I linked to, and other (non-Mercedes) references on the web, talk about lock-up having 3 states: disengaged, engaged and slipping (that was the oxymoron I referred to).

The suggestion is the slipping mode is the reason why you don't feel it in Merc's, and the transmission isn't fully locked until high speed. I'm pretty certain that mine is not fully locked at 70ish MPH, unless it unlocks at the merest whiff of the gas pedal.

There are articles about the newish 7 speed box which say it has lock-up on every gear.

 

[television]

No lock up on this document for the 7G see pge16 no lockup


http://www.mercedestechstore.com/pdfs/286_722.9/286 HO 722.9 062504.pdf

 

[Rory]

No lock up on this document for the 7G see pge16 no lockup


http://www.mercedestechstore.com/pdfs/286_722.9/286 HO 722.9 062504.pdf

It says it has lock-up, but it never fully locks. Seems odd - guess they know what they're doing, but intuitively it doesn't seem like a great idea for the lock-up clutch to always to be slipping.