Car Problem Reports
Mercedes-Benz S430 Failed Valve Body in Transmission
Mercedes-Benz S430 Problem
Average Mileage: 94,985 mi (52,700 mi - 149,000 mi)
Visitor, 2006 Mercedes-Benz S430, 107,100 mi
My valve body has been failing...(stuck in 3rd or higher gear), at stop after driving on a long stretch. I use to pull over, shut off engine, wait 1 minute and it would reset. Now it has failed all together and I learn it is a "dealer only" repair. When it failed it was stuck in 1st gear, maximum 20mph at 2000 rpm...Merecedes has replaced thousands of these valve bodies for that model year...this sholod be a "recall item". I cold drive an inexpensive vehicle and this would never happen...on an "S Class" Merecedes? MB is laughing on their way to the bank. Last one for me.
Visitor, 2006 Mercedes-Benz S430, 99,000 mi
transmission won't shift
Problem was the transmission jerked when slowing down or stopping. I believe this is called a harsh 2-1 downshift. Initially I was told by dealership that it would be necessary to replace the valvebody. However, for some reason they repaired it instead (I have read that valvebodies are in short supply). According to the invoice the valvebody shift valve was binding. The 2-1 downshift adaptation was high at - 19 cycles. It was necessary to program and SCN code trans control modules with latest version. The control module would not accept manual input of the EHS#. After several attempts, techremoved transmission. Tech replaced updated B1 and B3 clutch snap rings and removed B3 shift valve from valvebody and deburred for smooth operation (binding). The total repair came to $2111.50 ($361.50 parts and $1750 labor). I'd also like to mention, that at 39,000 miles, the car had a transmission leak, which I understand can cause a problem like this later on.
The valve body mounted inside the transmission fails causing the transmission to fail to shift. The problem usually starts with a hard second to first downshift.