alynch

Changed out the transmission fluid/filter and transmission mount last week. Wow, what a difference! Shifts are now silky-smooth. I suppose it's like the brakes where the change is so gradual you don't really notice until new pads are installed. Drained and replaced 8 quarts from the transmission and torque converter. With the transmission mount change there are now no vibrations at low rpms while accelerating and it no longer sounds like there is a hole in the exhaust! Found out after the fact (of course) that you don't have to remove the cross member to which the bottom of the mount is attached; just the three vertical bottom bolts (13mm) and the two horizontal bolts (16mm). All in all feels like a new car!

2013 C250 161,200 miles

xsever

I changed the transmission fluid last week as well and felt a tiny bit of improvement in shifting. I didn't change the mount since the car only has 50,000 km. Check out my report and pics here: 7G+ 4MATIC transmission fluid change report - MBWorld.org Forums

alynch

Good and informative write-up. I'm pretty sure the old fluid was from the factory and had not been previously changed. It was black. The transmission would not always shift smoothly when cold. Not a huge clunk but you could feel it shift especially when coming to a stop. Occasionally, the torque converter would not lock up immediately when required to do so. I had to shift into neutral and back to drive. When I drained the pan and the torque converter I measured the quantity of fluid (7qts 28ozs) and put back the same amount plus 16 ozs. I did not try to drain the oil cooler or the old fluid from the pipes. The new fluid (001-989-77-03-09) from MB was based on the VIN and was green in color. I ran the transmission up to 45C and shifted through all the gears several times. When I removed the fill tube about 12 ozs or so drained out and it was still green. As I mentioned before, I was stunned by the difference in shifting. I've changed transmission fluid on many vehicles in the past but never with such a marked change in operation. The good news is that both prior issues appear to be corrected and I have 300 miles on the new fluid. Looks like I can postpone that search for a new vehicle for a little while longer :-)