'06 E350 722.9 transmission "sticks" in 1st - PeachParts Mercedes-Benz Forum

Volvo Diesel · #1 11-05-2011, 07:16 PM

Car is my wife's 2006 MB E-350 wagon, NOT 4Matic, with 52,300 miles. Transmission is the 722.9 7-speed automatic, and has been serviced (fluid and filter change) twice at dealer (25,300 miles and 49,600 miles).

The transmission performs correctly 95% of the time. However, at least 5 times in the last 4 months, the transmission seems to randomly switch itself into manual mode, and the car won't shift past 1st gear (?-I'm assuming it's 1st...). It doesn't matter if it's the first start of the day, or the fourth start after running several errands--it has done it in both instances. When it does this, pushing the shift lever to the right (which seems to be how the manual states that you "clear" the manual selection) does not cause the car to go back into automatic mode. You have to bring car to a stop, place the car in park, turn off the car, and then turn the car back on again. If you do this, the transmission shifts fine. The 1-2 and 2-1 shifts sometime seem very slightly jerky to me. However, my daily driver is a '85 300 Turbodiesel with 250k+ miles, so the E-350 feels pretty much like a spaceship to me...

Anyone had similar issues, or worked on a car that was experiencing similar symptoms? I read a post on benzworld that suggested that electronics in the valve body may be the cause, and that the valve body may need to be replaced in the 7-speed, whereas with the 5-speed transmission, a conductor plate could be changed without changing the valve body. Can anyone confirm this? I plan on getting this looked at by the dealer or an indy (Benz specialist with STAR) soon--I'd like to know as much as possible beforehand so I can minimize the extent to which I will be $crewed...

Thanks--& sorry for the long post.