Quote Originally Posted by m_ron View Post
722.6 transmission on w210 chassis are very known for transmission failure, even though it has a lifetime trans fluid on it they should change the fluid every 30k miles.Try changing the trans fluid and filter and see it theres an improvement. make sure you buy the MB fluid and buy a mb trans dipstick,drop the pan and change the filter and gasket check for debris. To check the correct level you also need a laser thermometer.
On a sidenote, I noticed this "lifetime" no need for fluid change usually on Euro cars. When they advise this (no need to change), try not to heed their advice and change the ATF if you feel it is needed, especially with our local driving conditions.