Trans Oil

[sean sherry]

Pads you recomended and supplied work very well in our 2010 C Class Helmet. No Black Dust etc.

What oil should I use in the 5 speed Auto ?

Now 40000 Ks It has been quirky all it's life, and has had Soft Ware re loaded a couple of time by the Dealer. Now at times only, it is starting to shudder again on up shifts under light/ medium throttle, and under load.

An oil change and Filter worked wonders on my 722-306 4 speed 1981 SL 280'

Life time oil was fop to the Fleet users in Europe to contain running costs.
Mercedes had to back down on that one.

Can I use an upgraded Synthetic Oil,
Graham at Mercedes workshop had told me that the electronics sometimes get confused

I can't pick if it is the lock up CONVERTER OR ONE OF THE CLUTCHES IN THE bOX.

Also is there a drain plug in the Converter ?

I used to drill a i/8 th hole in Comadores and weld them up again for this cost cutting omission.
It was no big deal.

Thanks again......Sean

 

[Helmet]

We only use genuine MB fluid in 722.6 and 722.9 transmissions. You car may have a convertor drain plug. This is one of the mysteries of the world. Some c classes have it , some don't ?

 

[Styria]

Sean, it has only done 40K. kilometres - one would think that its operation would be faultless. Obviously, and without any criticism being levelled at anyone, especially not Helmet, what do you think your options are ? You're obviously very experienced with Autos, and I am wondering if you have something in mind ?

Unfortunately, I have no suggestions - is it a computer issue, or simply a mechanical one ? Interested to see how you get on. I rebuilt the box on Gleaming Beauty (6.9) about ten to fourteen years ago, and have experienced absolutely no problems. Regards Styria

 

[sean sherry]

My guess is Styria that a shuddering Clutch in an Auto is lack of pressure or most unlightley in this case , to much clearance in the Clutch or premature wear.
As everything is now computer controlled , Helmet has told me that there are no longer pressure take off points to check for correct pressure rises and stability during an up shift. Correct shift timing in the Box is critical. As this has been an issue from day one ( maybe day Two ) I feel that it is a Software malfunction. I'll talk to the Workshop Manager at Mercedes in Alexandria. He has looked at this a couple of times during the Warranty period. The Transmission was out twice trying to sort an Engine oil leak from the rear of the Block and cylinder Head.
Probably not a bearing on this issue.

 

[6.9forever]

If this thread were named "Shuddering clutch in W204 auto 5 speed", I would put my hand up and say I have the same symptom. Scary. Sean, you and I should compare notes. As my car is in Sydney, I could also consult the company-owned dealer in Alexandria. At 4.5 years old and 90,000km, I think it's very poor.

 

[sean sherry]

Yes David the same Transmission. I will try to speak to Graham at the Dealership this morning. He knows his job .
My car is the last of the 5 speeds and I believe it has the later modified Plastic Distributor Plate which contains all the shift Solenoids. At my low mileage I can't see the O Rings being brittle and leaking and causing bad electric contacts

 

[sean sherry]

Have had the Car over to Mercedes . Graham checked if a fault had been Flagged.. none. He said that he had reset something or other.
But in the way home over the Gladesville Bridge on a 5- 4 down shift there were two distinct thumps down the drive line. This was the original issue when the Car was near new. Seems like rearranging the Chairs on the Titanic !

Graham repeated that the 5 speeds sometimes get confused. Not much consolation if the Box needs premature big Dollars spent in the future

 

[BenzBoy]

Is this the same (or similar) 5 speed transmission I have on the ML320?
Mine has given the occasional thump when backing off on a light throttle but I'm told to expect that. Otherwise, it's silky smooth at all times. The transmission fluid has been changed twice now at 60K and 120K.
Regards,
Brian

 

[sean sherry]

PROBABLY BRIAN, a version of 722-6 or -9. My current advice is that 150000Ks
is about the limit of these Autos. Though an open road Car running in Top gear
would have an easier life.
My take on these modern sophisticated Transmissions. with their Duty Cycle Solenoids for ever adjusting the Line Pressure to suit the load conditions, to give smooth shifting, shorten the life of all such transmissions. The earlier designs without Electronics could be tailored to achieve quick clean positive shifts if they were a bit sloppy.

 

[BenzBoy]

PROBABLY BRIAN, a version of 722-6 or -9. My current advice is that 150000Ks
is about the limit of these Autos. Though an open road Car running in Top gear
would have an easier life.
My take on these modern sophisticated Transmissions. with their Duty Cycle Solenoids for ever adjusting the Line Pressure to suit the load conditions, to give smooth shifting, shorten the life of all such transmissions. The earlier designs without Electronics could be tailored to achieve quick clean positive shifts if they were a bit sloppy.

Oh dear - I had better buy a lotto ticket and hope ....
Regards,
Brian

 

[Helmet]

Oh dear - I had better buy a lotto ticket and hope ....
Regards,
Brian

No lottery ticket needed, the 722.6 in the ML is the most reliable transmission i know.

 

[sean sherry]

Is the 722-6 in the ML a more robust Box than our 722-6 2010 1.8 C Class ?

Brian can now go away and die Happy !

 

[Helmet]

Is the 722-6 in the ML a more robust Box than our 722-6 2010 1.8 C Class ?

Brian can now go away and die Happy !

Yes, we have never had one out in our shop. The C class are reliable as well. the main problem i find it when they get coolant in the transmission oil from the cooler in the radiator + sometimes one way clutches fail causing a harsh done shift.

 

[BenzBoy]

no lottery ticket needed, the 722.6 in the ml is the most reliable transmission i know.

phew!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[sean sherry]

And I thought that was only a Ford Falcon problem. We used to disconnect the cooler lines and install a separate Oil Cooler. Should I do that with our C Class or is it an ageing/ mileage issue ??????
The sprag Clutch (One Way) used to be only a D.G. Borg Warner issue and only behind some engines. and not the most powerful , 3.8 Lt Jaguars. !