Baldbloke
Active Member
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.
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.
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