auto transmission fluid replacement or not?

[Michael van der Veen]

As the proud new owner of a 2002 320CDI auto estate (the best car I have ever owned), I would welcome the views of the MB owners community on the desirability (and feasibility) or not of replacing the transmission fluid. The official Mercedes-Benz position is that the automatic gearbox is sealed for life and that replacement of the transmission fluid is a no-no. On the other hand I see from weblogs (mainly Stateside) and mentioned by Wikipedia that there are enthusiasts out there who doubt whether any transmission fluid can really last the expected life of the gearbox (hopefully several hundred thousand kilometres). As an ex-oil company employee (though non-technical) I also have my doubts. If anyone has experience of replacing the fluid, I would much appreciate hearing the background to the decision, whether it was difficult (can a competent technician do the job?) and what replacement fluid was used, Mercedes original spare part or oil company branded product. Finally, if this subject has been discussed before in the forum, please excuse my ignorance as a new member of the MBO community and just point me in the right direction! Thanks and regards to all fellow members, Michael.

 

[television]

Hello. The info that you have is out of date, there are no more sealed for life boxes. The norm now is that the fluid should be changed at 60k miles along with the filter. Most comment on the smoother changes once this has been done.

Malcolm

 

[type49]

I second that. MB dealers are now recommending this @ 60k, although some seem a bit slow to cotton on to it.

 

[Blobcat]

Quite a few MB dealers still say sealed for life, mine is one of them. However I had 4 ltrs changed out of the ~7 and a new filter as the Torque converter drain plug was deleted in 2000. If you want to do it yourself or just see the process Parrot of Doom has an excellent how to here; http://www.mercedesclub.org.uk/

 

[Parrot of Doom]

http://mbclub.co.uk/forums/showthread.php?t=23969

Its there actually

 

[Michael van der Veen]

Many thanks for all your help, cheers, Michael.

 

[Blobcat]

Thanks POD, don't know where my link came from. This is the one I meant; http://forums.mercedesclub.org.uk/showthread.php?t=16659

 

[THOMO]

ive just checked my gearbox oil its a toffee colour is that bad ?
im changing it anyway.

 

[Parrot of Doom]

Mine was a liquorice colour

If you're concerned, keep the old oil and send it off for analysis.

 

[Blobcat]

There is some info on colour in post No. 21 in the attached thread; http://forums.mercedesclub.org.uk/showthread.php?t=8109&page=2

 

[psmart]

If youve read the link posted by Blobcat, Ill fill you in with the experience, 5000 miles later, after replacing all the oils in the transmission, transfer case, and both axle housings.

Firstly, Ive got worn out or completely gone engine mountings, so Im getting a vibration through the car, but, the car now has 'take up' which it didnt used to have, ie. when accelerating from idle or cruising slowly with no gas, then hard accelerating, there is a jolt from the drive train! This never used to exist and has only come about since the change of oils! When I owned a Jeep Grand Cherokee, this drive train takeup was standard, but never on the ML, so replacing the oil has had a detrimental impact, if only because the old oil may have been hiding the problem! Once Ive replaced the engine mountings, will add further comments.

On just the gearbox, changes are smoother, but you get the odd 'malfunction', ie. it will hold onto a gear too long or jerk down. Havent re-checked the level yet and I am operating in sub-zero temperatures, but its worth a note that it may not be all glory days replacing the oils.

 

[230K]

If youve read the link posted by Blobcat, Ill fill you in with the experience, 5000 miles later, after replacing all the oils in the transmission, transfer case, and both axle housings.

Firstly, Ive got worn out or completely gone engine mountings, so Im getting a vibration through the car, but, the car now has 'take up' which it didnt used to have, ie. when accelerating from idle or cruising slowly with no gas, then hard accelerating, there is a jolt from the drive train! This never used to exist and has only come about since the change of oils! When I owned a Jeep Grand Cherokee, this drive train takeup was standard, but never on the ML, so replacing the oil has had a detrimental impact, if only because the old oil may have been hiding the problem! Once Ive replaced the engine mountings, will add further comments.

On just the gearbox, changes are smoother, but you get the odd 'malfunction', ie. it will hold onto a gear too long or jerk down. Havent re-checked the level yet and I am operating in sub-zero temperatures, but its worth a note that it may not be all glory days replacing the oils.

Hi

Are you sure the correct fluid was used during the transmission oil change, the electronic boxes need the correct MB Fluid. Also MB have a specific fluid that cures rough shifting on the ML me thinks, i will have a look for the part no.

Good Luck

230k

 

[aa1]

Nobody seems to have any information regarding changing all the gearbox oil, it appears that everybody accepts that mixing 4 litres of clean oil with 3 litres of dirty used oil constitutes an oil change! I'm afraid while I aggree it is better than nothing I cannot and will not accept that there is no method of getting the oil out of the torque convertor. I have done this before with a volvo by disconnecting the oil cooler pipe and starting the engine. this pumps the oil out slowly at idle speed and it can be replaced a litre at a time until the oil coming from the cooler pipe becomes clean. I would add that this is after draining and replacing the oil in the gearbox pan. I have not attempted this on a merc but I will be in the near future. AA

 

[psmart]

230K, thanks, I did all the work myself and bought all the correct oils and magnet, seals etc direct from Mercedes in Dusseldorf, with the chap there being very helpful to ensure I had the uptodate parts. The only oil that was not Merc was for the Axle housings, but there was no specific part for this.

AA1, if your method works, let us know. I dropped the pan twice to ensure I diluted the dirty three litres (ie. I replaced the oil twice, until it stayed red after a run). Seems anybody with a newer 722.6 transmission will have this problem as you cant drain the torque convertor without dropping the box!!!! Makes sense.... not.... but there again, Merc were trying to tell us that these boxes were sealed for life! Probably one of their cost cutting exercises performed by a bean counter and not an engineer!!!

Well, temperature has started to drop in Austria where I keep the ML, so will see if temperature is the key to the 2 minor malfunctions etc. Now that I have a sealey, I might just drain the system a third time to see the state of the oil and get a better flush!

 

[type49]

Nobody seems to have any information regarding changing all the gearbox oil, it appears that everybody accepts that mixing 4 litres of clean oil with 3 litres of dirty used oil constitutes an oil change! I'm afraid while I aggree it is better than nothing I cannot and will not accept that there is no method of getting the oil out of the torque convertor. I have done this before with a volvo by disconnecting the oil cooler pipe and starting the engine. this pumps the oil out slowly at idle speed and it can be replaced a litre at a time until the oil coming from the cooler pipe becomes clean. I would add that this is after draining and replacing the oil in the gearbox pan. I have not attempted this on a merc but I will be in the near future. AA

The oil can be changed this way if you access to a ramp. Carefull though, as the oil pumps out quicker than the thin dipstick tube allows the new oil in. Be sensible & you should'nt have a problem. I can't remember which side of the box is in & which is out though. It's easier to get to at the rad end but harder to clear up the mess afterwards!

 

[aa1]

The way I did the volvo was to push a rubber hose over the pipe at the cooler and drain 1 litre at a time into a marked gallon container, then stopping the engine replace with new oil. It is a little time consuming but it worked on the volvo and no mess. AA

 

[Glenn Smith]

Hello. The info that you have is out of date, there are no more sealed for life boxes. The norm now is that the fluid should be changed at 60k miles along with the filter. Most comment on the smoother changes once this has been done.

Malcolm

I think officialy it is still not a service item, Mb atf is the cheapest suitable type of oil that i could find so i wpuld recommend that. After changing mine the changes were slightly worse (i had had the battery disconnected) the control unit took a while to adapt itself but now the gearchanges are virtually perfect and incredibly smooth despite it's 146000 miles.

 

[The Hooded Claw]

Nobody seems to have any information regarding changing all the gearbox oil, it appears that everybody accepts that mixing 4 litres of clean oil with 3 litres of dirty used oil constitutes an oil change! I'm afraid while I aggree it is better than nothing I cannot and will not accept that there is no method of getting the oil out of the torque convertor. I have done this before with a volvo by disconnecting the oil cooler pipe and starting the engine. this pumps the oil out slowly at idle speed and it can be replaced a litre at a time until the oil coming from the cooler pipe becomes clean. I would add that this is after draining and replacing the oil in the gearbox pan. I have not attempted this on a merc but I will be in the near future. AA

Now THAT^^^^^^^^^^^^^ is exactly what my mate did fer me when I had that Tranny Oil leak a few weeks ago.......Discon at the rad end fix a rubber hose over the end start the engine & measure it out into a gallon drum.....when the Oil comin out is the same colour as is going in recon the cooler pipe & top up as necessary .............(as the guy in 2010 says " Easy as cake or piece of pie")

Keith,

 

[doshbass]

Hi All,

Can anyone tell me if this gearbox fluid replacement procedure is the same for a 211 320CDI.

Many Thanks

 

[television]

Yes if the car has the 5 speed 722.6 box. it is the same