W212 7G+ ATF oil change - do I drain the torque converter?

[btjtaylor]

Hi all

I have a 2011 S212 E350 BlueEff estate which I believe has the 7G+ box

I'm looking to change the oil in my auto box as part of the servicing as its due (last done 5 years ago, and according to the service schedule it's now due)

I've spoken to a dealer who is listing parts on ebay (cheapest place I can find) and they told me this kit is correct:

Genuine Mercedes-Benz 722.9 Automatic Stop-Start Gear Box Service Kit ZB79PAC | eBay

Includes: Gear Box Filter, Rubber Sump Gasket, Copper Washer, Flow Pipe, 6 Sump Pan Bolts & 6 Bottles of BLUE Transmission oil 236.15. Smart Parts. Suitable for various models with 722.9 stop/start automatic models From 2011.

www.ebay.co.uk

The car doesn't actually have "stop/start" but I believe this is just one way to identify 7G+ over 7G

My question - do I need to drain the torque converter? I found a video online which basically shows that you have to hand crank the engine to spin the TC round to get to the drain plug. Then I found some other pages that said that it might not have one, or I might have to remove other parts to access it. It's all a bit confusing!
If I paid a main dealer to do it - what would they do? I'm happy to do as MB recommend.

It seems like if I DID drain the TC, i'd need more than the 6L of oil the kit provides.

On a side note - is it possible to look at service manuals somewhere? I have a lot of experience with Audis and you can get this stuff through ElsaWin (Audi workshop repair software) but I dont know if ther's an MB equivalent?

Thanks in advance
Ben

 

[Bellow]

My question - do I need to drain the torque converter? I found a video online which basically shows that you have to hand crank the engine to spin the TC round to get to the drain plug. Then I found some other pages that said that it might not have one, or I might have to remove other parts to access it. It's all a bit confusing!
If I paid a main dealer to do it - what would they do? I'm happy to do as MB recommend.

'Draining' a TC is a misnomer - they are flushed thorough with fresh fluid to displace the old.
Not tackling the TC only replaces about half the fluid so my preference is to include the TC in a fluid change - others have different views (but wouldn't accept only half of their engine oil being changed).
Not sure what is 'standard' from a main dealer but an indie should be able to do whichever method you prefer - possibly a main dealer can also.

It seems like if I DID drain the TC, i'd need more than the 6L of oil the kit provides.

Including the TC will be more than 6 litres I'd guess. Probably double that is required.

 

[KennyN]

Generally speaking just draining the sump and replacing the filter will only remove 50 - 60% of the fluid as the TC , cooler and its lines hold the remainder.

Going to replacing the ATF on the Cayenne tomorrow (if it stops pi$$ing down) and have ordered 15L of oil as i will be using the first fill after the filter replacement to dilute the remainder of the old oil and then drain and fill with the remainder of the ATF which should do the job well enough for my piece of mind.

I ordered the Febi sump gasket , drain plug and filter from Autodoc for £23 delivered , 15L of the correct oil was sourced from Opie oils for £130.

The oil cooler will have a thermostat so you need to ensure the oil is up to temp to open the stat (90 degrees C on the Porker ) to allow full circulation on the fluid.

K

 

[jasonh]

I very much doubt a MB dealer will drain the TC. Some cars have a drain screw, some don't. The MB instructions says if there is a drain screw then drain the TC. It's messy and you have to very carefully turn the engine by hand to find the screw.

You only have to get the car up to 90C if you remove/replace the transmission cooler, otherwise just the 45C to set the level.

6 litres should be plenty if you don't do the TC but if you do the total fill of the transmission is between 9 and 9.7 litres. You won't get the whole lot out but you'll need more than 6 litres.

There is a really good write up on this forum or another UK MB forum, I think by a chap called Geoff, of doing a 772.9 gearbox oil change.

Some people make a big fuss about changing the transmission oil but MB only allow 0.9 hours to do the job.

 

[geoffus]

I did mine a while back, it’s easy to do although can be messy, you will need around 9 litres if you drain the TC.

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[W1ghty]

This was my diy attempt on the 7g box on my w211

Mercedes E320cdi 722.9 DIY Gearbox oil change

Just finished the gearbox oil change . I'm embarrassed to say it probably took about 5 hours over yesterday afternoon and this morning . God know where the time went , probably lots of tool retrieval from the garage and a healthy dose of second guessing . I didn't intend to start yesterday ...

forums.mercedesclub.org.uk

 

[btjtaylor]

Thanks for the replies all - Geoff's video was very useful! I will order 10L of oil just to be on the safe side. Nothing worse than running out mid job and having to wait for more to arrive or pay way over the odds from a local supplier.

I will order all the service parts next week when my cash flow is looking a bit better just paid best pat of £500 for 4x new tyres (Eagle F1 Asymmetric, they're awesome), then report back with how I got on. Fortunately i've done a few ATF changes in the past on my audi and have a computer with Xentry up and running so I think i'll be OK.

 

[markjay]

I very much doubt a MB dealer will drain the TC. Some cars have a drain screw, some don't. The MB instructions says if there is a drain screw then drain the TC. It's messy and you have to very carefully turn the engine by hand to find the screw.

MB Brooklands told me they drained the TC on my car (7g+), via the drain plug. That said, I didn't ask them if they would have 'flushed through' the TC if my car didn't have the drain plug, so I don't know the answer...

 

[Petrol Pete]

You guys with drain plugs in you TC's are making me jealous I would still like to have a chat with the accountant who decided to omit it from the TC in my transmission .

I too have watched various gearbox service videos and the ones that use a a hand pump and a rigged up connection of some sort always seem to do a good job of flushing everything out.

My understanding of garages not draining the TC even if it has a plug is time , it takes a while for all the fluid to drain out and if the garage has only one or 2 lifts it's time 'in the air' that they just don't want to spend.

 

[BlackC55]

I did mine a while back, it’s easy to do although can be messy, you will need around 9 litres if you drain the TC.

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We do that job for £200 all in. We buy our parts and fluid in bulk to it allows us to be very competitive price wise.

 

[MrGreedy]

Reading this thread I was about to say good independent specialists like PCS do this for around the £200 mark, and therefore I went there just under a year ago as it's not worth the risk and effort for me personally faffing around under the car, especially without a proper lift.

I think BlackC55 previously mentions somewhere that in his workshop they experience the real risk when doing these of a problematic bolt or two on the sump pan, and therefore the ability to rectify this if you need to drill out, re-thread etc, which will be a monumental PITA if you don't have a lift.

 

[geoffus]

Reading this thread I was about to say good independent specialists like PCS do this for around the £200 mark, and therefore I went there just under a year ago as it's not worth the risk and effort for me personally faffing around under the car, especially without a proper lift.

I think BlackC55 previously mentions somewhere that in his workshop they experience the real risk when doing these of a problematic bolt or two on the sump pan, and therefore the ability to rectify this if you need to drill out, re-thread etc, which will be a monumental PITA if you don't have a lift.

I completely agree, to do this job with Mercedes genuine parts is brilliant value and not worth even jacking the car up, but if you not able to go to PCS for any reason then it can be done reasonably, especially if your Mercedes dealership wants to charge £400 plus.
As regards problem bolts, most are not even tight and came undone with little effort.

 

[W1ghty]

My DIY attempts on things have started because I want to up my game mechanically and I like tinkering .
Ive done both my CLK’s 5g and the E’s 7g , twice each now . I get a lot of satisfaction getting the job done at home especially in the summer .
I think the E was £100 diy and the CLK maybe about £80 last time i did them .

 

[Justintyme]

Just changed the ATF in my 7g, (and on the ground at that...biggest problem was getting up high enough to work comfortably ) Job is straight forward enough. Remove sump drain stud, knock over the fluid level tube, allow it to drain completely.( catching all the fluid, very important as you will need to know how much to put back ) Remove sump bolts, drop it down, replace the filter. Remove the electric pump to access the TC drain stud, and allow the TC to drain. Replace everything with in basically reverse order, Run it to 45c to check the fluid level is correct, and adjust if not. Bingo, job done.

 

[geoffus]

Just changed the ATF in my 7g, (and on the ground at that...biggest problem was getting up high enough to work comfortably ) Job is straight forward enough. Remove sump drain stud, knock over the fluid level tube, allow it to drain completely.( catching all the fluid, very important as you will need to know how much to put back ) Remove sump bolts, drop it down, replace the filter. Remove the electric pump to access the TC drain stud, and allow the TC to drain. Replace everything with in basically reverse order, Run it to 45c to check the fluid level is correct, and adjust if not. Bingo, job done.

I agree, hardest job is getting it jacked up, everything else is straight forward.

 

[btjtaylor]

Managed to get this done this weekend without too much trouble

I basically just followed along to this video

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I don't have the auxiliary oil pump (start/stop) so I didnt have that to remove, just remove the rubber bung to get to the torque converter plug.
I had difficulty getting access to rotate the engine to spin the torque converter but managed to get it from below rather than trying from above (on the E350 CDI there is basically no access down the front of the engine - on the 4 cylinder models you can do that a bit easier).
I pumped in 6 litres of oil and started the car and waited patiently for it to get up to 45c (it took ages! didnt help it was a very cold day)
Once 45 degrees was reached I pumped in the remaining 3 litres and went through the gears. Once this was done there was a slow drip of oil coming out which is how its supposed to be.

Drives same as before, no issues noticed. I do find the car changes gears quite roughly from cold on a cold day, so I will see if this corrects it ... the oil was dirty but not horrible (could still see a bit of the blue/green colour).

 

[Justintyme]

Managed to get this done this weekend without too much trouble

I basically just followed along to this video

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I don't have the auxiliary oil pump (start/stop) so I didnt have that to remove, just remove the rubber bung to get to the torque converter plug.
I had difficulty getting access to rotate the engine to spin the torque converter but managed to get it from below rather than trying from above (on the E350 CDI there is basically no access down the front of the engine - on the 4 cylinder models you can do that a bit easier).
I pumped in 6 litres of oil and started the car and waited patiently for it to get up to 45c (it took ages! didnt help it was a very cold day)
Once 45 degrees was reached I pumped in the remaining 3 litres and went through the gears. Once this was done there was a slow drip of oil coming out which is how its supposed to be.

Drives same as before, no issues noticed. I do find the car changes gears quite roughly from cold on a cold day, so I will see if this corrects it ... the oil was dirty but not horrible (could still see a bit of the blue/green colour).

And I presume you used the Meyle kit, as I did? They ( Meyle ) have some very interesting videos. easy to follow.. Only problem I have with it is they do not show how to drain the trans cooling radiator and pipes.....but I guess it does not hold a lot of fluid. I'd say that it can be done simply enough, disconnect both pipes at the trans, and pump in enough fluid until the new fluid comes out the other pipe. Would have to be done at the beginning, I'd say.

 

[btjtaylor]

I used genuine Mercedes parts not Meyle. There wasn't much difference in price aftermarket parts vs. OEM so I just went with OEM stuff.

Mercedes-Benz A0049903512 for sale online | eBay

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For anyone curious for the filling tool I used this one from Sealey. Only disadvantage was having to stop a few times to refill the bottle. You can get models with a bigger capacity but the prices were stupid (Think laser wanted ~230 quid for their 7 litre one)

Sealey VS70095 Transmission Oil Filling System 3L

Sealey Transmission Oil Filling System 3L Transmission VS70095

workshopping.co.uk