Mercedes E320cdi 722.9 DIY Gearbox oil change

[Jim2]

Jesus buddy , if I knew that you had it so nailed down you could have done it . Your description is bang on and as you know sounds very straightforward until you are covered in ATF and gravel and rolling around under the car !
As to monitoring between changes you don't do , maybe an Indy with Star might in a B service but I won't .

It was only "Nailed Down" because of your description of it...Best description of it I have got so far. I have never done a fluid change on a 722.9 box,,,,and what I could see on the Net, was very intimidating. But now, I feel that I could tackle it myself if I had to. In all fairness, the 722.6 box was a blind leap for me too..especially when several local Indy's told me (politely but firmly) to get myself and my MB- needing- an- Trans Oil change to get the hell out of their the premises ASAP. There is a decided air of mystery about MB servicing where I live. So took a chance and jumped in...and it worked out fine !!!! Surprise, Surprise.Now I am getting a bit more confident about it. And Like you said, when you do it once, next time is easier !!! And I know very well what it means to be lying on the flat of your back, with various liquids leaking down on top of you,and dirt and grit getting into your eye's and mouth ( until you learn to keep it shut!! ) When doing the 722.6...I was more than careful, about getting hit by draining oil....Oil drained, sump off.....not a drop on me V Happy !!! Then I pried the filter off....and what was left in that ran down my sleeve, passed the elbow, and managed to lubricate every thing from the neck down !! So I know very well where you are coming from..

 

[Wighty]

Noticed what look like some oil wetness and a drip on the back of the gearbox sump rubber seal , where it meets the exhaust mount .
I could probably have left it but with some good weather forecast the other day I ordered a new sump seal some stretch bolts and a new filter . I already had some Fuchs atf in the garage .
I think when I changed everything last year I didn’t remove the exhaust mount bracket which slightly limits space and this may have prevented the seal sitting squarely ?
Anyway all of it was done in 2-3 hours . I saved ages by knowing where to find the transmission temperature in the icarsoft.
Hopefully all is now well . I had done 8000 miles since I changed the filter but this now resets the clock again .
When I do the CLK atf and filter soon on the 5g box that should be a doddle.

 

[D5meister]

Hi wighty when you did the atf final level,was the car on ramps as per earlier image?

 

[Wighty]

Hi wighty when you did the atf final level,was the car on ramps as per earlier image?

It was buddy , I used a jack to lift the front a couple of inches and a magnetic spirit level on the sump to achieve a close enough for government work outcome

 

[Oldspanners]

It was buddy , I used a jack to lift the front a couple of inches and a magnetic spirit level on the sump to achieve a close enough for government work outcome

Had to have a drive this afternoon of about 30KMs to collect "necessities" and noticed the difference after the flush.
I was really surprised and impressed (so far) at the difference in shift quality which I would have said before was very smooth. It seems now to be immediate and imperceptible even when reversing out from cold the gear engaging unnoticeably. Full acceleration, kick down, Tiptronic and just pottering about all better, I did expect perhaps a little difference as the oil wasn't too bad but this is a noticeable difference. I put this down to getting the level spot on with the iCarsoft, whereas before it was done after a long run hoping the temperature was correct.
Thanks again for the info.

 

[Wighty]

Had to have a drive this afternoon of about 30KMs to collect "necessities" and noticed the difference after the flush.
I was really surprised and impressed (so far) at the difference in shift quality which I would have said before was very smooth. It seems now to be immediate and imperceptible even when reversing out from cold the gear engaging unnoticeably. Full acceleration, kick down, Tiptronic and just pottering about all better, I did expect perhaps a little difference as the oil wasn't too bad but this is a noticeable difference. I put this down to getting the level spot on with the iCarsoft, whereas before it was done after a long run hoping the temperature was correct.
Thanks again for the info.

That’s interesting about using the icarsoft for temperature on the 5g , I’ve only used the dipstick . Is the correct 5g temp 80 degrees ?
You are right , there’s something about a gearbox oil change for sharpening up changes

 

[Oldspanners]

That’s interesting about using the icarsoft for temperature on the 5g , I’ve only used the dipstick . Is the correct 5g temp 80 degrees ?
You are right , there’s something about a gearbox oil change for sharpening up changes

From all that I've read yes, the dip stick markings showed that.
The iCarsoft showed about 80 to 83C dropping to around 35 to 40C as I cycled through P,R,N,D with my foot on the brake and the hand brake on.
Difficult to say but it may have been a little low before as now I've driven it since the response is immediate. There was very little sludge in the pan any no noticeable metal particles and a clean magnet. The oil sucked out of the sump was of course the darkest and it took 5 litres before I was satisfied the oil appearing in the tube was the right colour.
I was expecting a sort of psychological effect but I'm impressed by the change it has made. Look forward to longer trips (like everyone else) to confirm this.
Oh, I think I'll do a transmission oil change at the same time as the engine oil if it stays this good.

 

[Jim2]

From all that I've read yes, the dip stick markings showed that.
The iCarsoft showed about 80 to 83C dropping to around 35 to 40C as I cycled through P,R,N,D with my foot on the brake and the hand brake on.
Difficult to say but it may have been a little low before as now I've driven it since the response is immediate. There was very little sludge in the pan any no noticeable metal particles and a clean magnet. The oil sucked out of the sump was of course the darkest and it took 5 litres before I was satisfied the oil appearing in the tube was the right colour.
I was expecting a sort of psychological effect but I'm impressed by the change it has made. Look forward to longer trips (like everyone else) to confirm this.
Oh, I think I'll do a transmission oil change at the same time as the engine oil if it stays this good.

If you want to do a "quickie" trans oil change ( with out filter change ) have it level on stands and disconnect the oil cooler pipe coming from the rad back to the box, rig a plastic pipe to the steel pipe, to direct the draining oil into a container. Start engine, handbrake on, foot on brake, move lever to "D" and let it pump out 2 litres, Switch off, engine, replace the 2 ltrs drained with fresh fluid, and repeat until you have say 10 ltrs replaced, Refit cooler pipe to the transmission. Job done. If you DO drain at these relatively short intervals, then the color will not have changed very much. In a trans with big mileage between changes, you would have to keep pumping fresh fluid through the system until the fresh fluid makes it's appearance at the drain pipe. One advantage of this method is that the TC and radiator fluid get changed too. Its unbelievable the difference a fluid change can make, as you ( and I ) have found out

 

[D5meister]

Some articles speak of a thermostat ~80°C before the rad is in the loop.
Is that true on w205 7speed?

The return pipe has orings which are..

 

[Wighty]

Some articles speak of a thermostat ~80°C before the rad is in the loop.
Is that true on w205 7speed?

The return pipe has orings which are..

Can’t answer that buddy

 

[davemercedes]

Well done, Wighty. I wouldn't worry for a moment about the time it took you because I'm absolutely sure you've left it clean enough to eat under the bonnet and had a satisfactory look around everywhere. And don't you get that satisfactory feeling of a job well done when the best person you know did it, eh?

Just fyi I had my ATF done at Mercland and I needed to sit and wait for it. I think they took 2 1/2 hours from start to finish so you've done okay anyway.

 

[Jim2]

Some articles speak of a thermostat ~80°C before the rad is in the loop.
Is that true on w205 7speed?

The return pipe has orings which are..

For the 722.6 5 Speed, the temp for correct oil level checking is 80c. Re "O" ring, see attached pic, it shows the rad cooler pipe connection to the 722.6 transmission., no "O" ring, just two copper washers. For the 7 speed box, ike Wighty, I dont know either. Sorry.

 

[D5meister]

I see. Looks like a banjo.
Im still curious bout the stat, my temp for level is 45°C im told.
Are the pump electrical connections easily accessed? Was thinking pull rtn hose and run the pump by putting 12v on it and pumping all of it out in one go. Then filter swap and refil.

 

[Jim2]

I see. Looks like a banjo.
Im still curious bout the stat, my temp for level is 45°C im told.
Are the pump electrical connections easily accessed? Was thinking pull rtn hose and run the pump by putting 12v on it and pumping all of it out in one go. Then filter swap and refil.

Yes its a banjo connection.And standard on the 722.6 trans,but with the 7 speed...I have no experience Sorry. But I'm pretty sure that some one with 7 sp trans will be along soon to advise you. I have by-passed the electrical system in other makes of cars, but unless I was 100% sure, I would not attempt it on my Merc though. On the 722.6 trans, the oil is pumped out by running the engine while engaged in "D", that does the trick.

 

[Oldspanners]

I see. Looks like a banjo.
Im still curious bout the stat, my temp for level is 45°C im told.
Are the pump electrical connections easily accessed? Was thinking pull rtn hose and run the pump by putting 12v on it and pumping all of it out in one go. Then filter swap and refil.

Have a look at this the most comprehensive I've found.

 

[Jim2]

Have a look at this the most comprehensive I've found.

That does the trick allright, Oldspanners. Thanks for posting ( just in case my next one will have the 722.9 trans... )

 

[D5meister]

Hi thanks for the vid - hes a good lad seems to know what hees doing, I guess there is no stat if he is fushing it thru, it will go into the TC and thru rad and out.

The orings I mentioned are in the attached still from the vid. It is recommened on the procedure to swap both orings.

Saving my ATF redo for when I have a long day with good weather and no wind, keep the dust from swamping the box while pan is off.

 

[Wighty]

Hi thanks for the vid - hes a good lad seems to know what hees doing, I guess there is no stat if he is fushing it thru, it will go into the TC and thru rad and out.

The orings I mentioned are in the attached still from the vid. It is recommened on the procedure to swap both orings.

Saving my ATF redo for when I have a long day with good weather and no wind, keep the dust from swamping the box while pan is off.

Next week buddy , Tuesday looks good . I’m probably going to do the CLK 5g atf/filter then as well

 

[D5meister]

Did mine today. 9l out 9l in. So not total flush. I got 4.5l from the drain from the pan. I pulled the rad return hose and used short length of garden hose over the free pipe end with a zip tie. I replaced both orings on pipe end afterwards.
Added 6.5l started engine and pumped out 2l then shut off engine.
Added 2l pumped 2l out of pipe. Did this until all 9l supplied was in and about 8.5 drained. Should be 9.5l in just now.
Car level on pan in x and y.
Need thermometer to do the final drain.
Magnet was a bit furry. Bit sludgy in tray.
When i pulled the return pipe, i undid saddle clip holding pipes an the saddle clip further round by the passendger wheel. This allows the metal pipe to clear without bending it.
My pan has shamfer and is green tube.
Next time i will drain tc and put about 12l through as full flush.
Hardest thing is crawling about on back!
Getting bit long in tooth for this stuff!

 

[davemercedes]

Can't do this any more. And I'm just a bit jealous!
Well done