722.9 box oil and filter change yesterday

Baldbloke

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Apr 8, 2016
Messages
542
Location
Moray
Car
E Class Estate 320CDI Elegance 2007 Non- ADS
Bought a 2007 car secondhand E class wagon 320 CDI V6 with 25 K on the odometer from Jersey a few years ago. Car had just been serviced and had had the Auto box oil and filter changed too before I collected it. All by the Jersey main dealer. The car was from a friend. During the next engine oil change I saw that the auto box was leaking a little at the gasket so realised it would need addressed but kept putting it off until yesterday and with 70,000 miles on the clock.
Not a difficult job after studying a really good Youtube video of an Australian doing a similar box:


All the detail is in the video except the torque and 180 degree final turn needed for the sump stretch bolts. The chap doing the video replaced the MB bolts with his own steel allen headed bolts and put some anti corrosion material on them to stop the seizing into the block. I learnt off another video that the correct torque for the MB bolts is 4 Nm + a 180 turn afterwards. Don't use the old ones and don't overdo it or you'll snap them off.

I bought an adapter off eBay to refill the sump and an electric pump to transfer the new fluid. I also bought a cheap temperature sensor to check the oil was at the correct temperature (45 C) for removing the excess transmission fluid after running the box through all its gears a few times.
I also bought a kit from a MB dealer that included the new stretch bolts, washers, a new screw plug for the torque converter, a filter, 2 magnets, the level plug that fits over the drain hole and the necessary fluid.

links:
Genuine Mercedes-Benz 722.9 Automatic Gear Box Oil and Filter Service Kit NEW!
( 173183505351 )

722.9 Auto Transmission Fluid Filling Line Filler Adapter Fit for Mercedes Benz
( 183713753313 ) I've seen it even cheaper elsewhere

Electric Liquid Fuel Syphon Pump Automatic Transfer Gas Oil Water Battery Supply
( 264225396619 ) Very slow but did the job. In the video the chap just gently pressurises the container from a compressor to transfer the fluid.

Digital Laser Infrared Temperature Gun Thermometer Thermal Heat Sensor Gauge IR
( 153415263154 )

I had no issues until I realised the MB dealer had sold me insufficient fluid, as I drained 6.5 litres out. The kit I bought only had 6 litres of new fluid to replace it with. My fault for not checking beforehand, but it did made me wonder how thorough a job some dealers actually do. With the torque converter and a flush of the line I used nearly 11 litres and suspect after doing the necessary drain before finishing that the box and everything else the box/ torque converter lines and cooler retain around 9 litres. A hell of a lot of fluid comes out of the torque converter drain, so there's no point in doing half a job as your new fluid will be mixing with all the crap left there.

So, in spite of my box being so short of fluid, the fluid was still relatively transparent and it was working without issues. Maybe I was lucky. There was only one magnet in my sump (with very little debris on it) but as the kit came with two, I stuck them both in.
I did see the later version of the 722.9 box with stop/start function uses a different fluid. Blue in colour I believe. My earlier version took the red variety.

I don't know whether I saved myself much money but I certainly learnt it's one of the easier jobs and not something to be frightened of.
 
Last edited:

kid-jensen

MB Enthusiast
Joined
Dec 16, 2002
Messages
1,239
Location
Epsom Downs
Car
ML 320 W164
Well done! I finally worked up the enthusiasm to do mine last week. I'd been dreading it but it turned out to be easy enough, just incredibly messy.

Didn't flush the oil cooler, it was too much trouble, but I did find the torque converter drain plug, which surprised me as often they don't have one.

Another DIY adventure under my belt......now for the engine mount!
 

Justintyme

Active Member
Joined
Feb 3, 2018
Messages
915
Location
Ireland
Car
Mercedes Benz w212 E Class
Bought a 2007 car secondhand E class wagon 320 CDI V6 with 25 K on the odometer from Jersey a few years ago. Car had just been serviced and had had the Auto box oil and filter changed too before I collected it. All by the Jersey main dealer. The car was from a friend. During the next engine oil change I saw that the auto box was leaking a little at the gasket so realised it would need addressed but kept putting it off until yesterday and with 70,000 miles on the clock.
Not a difficult job after studying a really good Youtube video of an Australian doing a similar box:


All the detail is in the video except the torque and 180 degree final turn needed for the sump stretch bolts. The chap doing the video replaced the MB bolts with his own steel allen headed bolts and put some anti corrosion material on them to stop the seizing into the block. I learnt off another video that the correct torque for the MB bolts is 4 Nm + a 180 turn afterwards. Don't use the old ones and don't overdo it or you'll snap them off.

I bought an adapter off eBay to refill the sump and an electric pump to transfer the new fluid. I also bought a cheap temperature sensor to check the oil was at the correct temperature (45 C) for removing the excess transmission fluid after running the box through all its gears a few times.
I also bought a kit from a MB dealer that included the new stretch bolts, washers, a new screw plug for the torque converter, a filter, 2 magnets, the level plug that fits over the drain hole and the necessary fluid.

links:
Genuine Mercedes-Benz 722.9 Automatic Gear Box Oil and Filter Service Kit NEW!
( 173183505351 )

722.9 Auto Transmission Fluid Filling Line Filler Adapter Fit for Mercedes Benz
( 183713753313 ) I've seen it even cheaper elsewhere

Electric Liquid Fuel Syphon Pump Automatic Transfer Gas Oil Water Battery Supply
( 264225396619 ) Very slow but did the job. In the video the chap just gently pressurises the container from a compressor to transfer the fluid.

Digital Laser Infrared Temperature Gun Thermometer Thermal Heat Sensor Gauge IR
( 153415263154 )

I had no issues until I realised the MB dealer had sold me insufficient fluid, as I drained 6.5 litres out. The kit I bought only had 6 litres of new fluid to replace it with. My fault for not checking beforehand, but it did made me wonder how thorough a job some dealers actually do. With the torque converter and a flush of the line I used nearly 11 litres and suspect after doing the necessary drain before finishing that the box and everything else the box/ torque converter lines and cooler retain around 9 litres. A hell of a lot of fluid comes out of the torque converter drain, so there's no point in doing half a job as your new fluid will be mixing with all the crap left there.

So, in spite of my box being so short of fluid, the fluid was still relatively transparent and it was working without issues. Maybe I was lucky. There was only one magnet in my sump (with very little debris on it) but as the kit came with two, I stuck them both in.
I did see the later version of the 722.9 box with stop/start function uses a different fluid. Blue in colour I believe. My earlier version took the red variety.

I don't know whether I saved myself much money but I certainly learnt it's one of the easier jobs and not something to be frightened of.[/QUOTE
"Well Done" on your first MB Transmission fluid change, and as you have found out, it's not rocket science.None the less, it need's more care and attention than an engine oil change, and do not under no circumstances, use any cloth's that contain microfibre's......they are death to an MB auto transmission. Does your car have the 722.6 or 722.9 trans? I presume that you drained the TC via it's drain plug? Turning the engine until the drain plug aligns with the access slot? You mention the level check as 45c, I think that you meant 80C. It comes as a surprise ( as you found out ) to discover just how much fluid you need to do a full flush on these boxe's, you would need 12 ltrs to be on the safe side. I am not too sure about adding an extra magnet to the sump...personally, I would keep to the manufacturers recommendation's. After the change, did you find any difference in the performance ?
Again, "Well Done", here's to many miles happy motoring !!!
 
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Baldbloke

Baldbloke

Active Member
Joined
Apr 8, 2016
Messages
542
Location
Moray
Car
E Class Estate 320CDI Elegance 2007 Non- ADS
I did check on the temperature through a few videos, and everyone seemed to concur on 45 C.

All the autoboxes in the videos had two magnets. I suspect the dealer didn’t replace one of mine.

No real difference after the fluid replacement, but it was a smooth transmission beforehand.
 

Justintyme

Active Member
Joined
Feb 3, 2018
Messages
915
Location
Ireland
Car
Mercedes Benz w212 E Class
I did check on the temperature through a few videos, and everyone seemed to concur on 45 C.

All the autoboxes in the videos had two magnets. I suspect the dealer didn’t replace one of mine.

No real difference after the fluid replacement, but it was a smooth transmission beforehand.
As it's the 722.9 trans, 45c is probably the right temp to check the level at. Mine is a 2010 W212 E Class, with the 722.6 Trans, and it has to be checked at 80c. Only has one magnet as well ( earlier one's I believe did not have any magnet at all ) and its a completely different set up re flushing / filling etc. It's filled via the dipstick tube, and it's relatively easy to check the level anytime. The fluid colour is red, and that's what I replaced it with. Other than that, I did pretty much the same job as you. Got a kit, jacked up the car, and got to work. Was my 1st time too, so was a little bit apprehensive, but will not mind doing it again. There are far worse job's to have to do in a Mercedes. !!!:):):)
 

Petrol Pete

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Nov 11, 2016
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7,324
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Petrol stations ...everywhere
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C55 AMG Wagon
Well done! I finally worked up the enthusiasm to do mine last week. I'd been dreading it but it turned out to be easy enough, just incredibly messy.

Didn't flush the oil cooler, it was too much trouble, but I did find the torque converter drain plug, which surprised me as often they don't have one.

Another DIY adventure under my belt......now for the engine mount!
Engine mounts are easy...just buy the offset spanner online first. Check if you need 16mm or 17mm before ordering. Job would have been almost impossible on my M113 V8 without it. Disclaimer: I actually made mine based on pictures on the internet, but the 'spanner' is widely available.
 

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