| first off if your car doesnt shift to drive, park or neutral, the trans isnt the issue. you have on the side of the trans whats called an ISM (intelligent servo motor) which is sent a signal from your shifter on the steering column to shift the trans. when that fails, you cant shift out of park and usually get the warning on the cluster that says drive to workshop without changing gears. the ism connects to a shaft on the side of the trans and will turn a shaft that moves a valve in the valve body (the valve is a sensor that detects what gear your in). only other possible causes is the sensor in the valve body is bad and you need a new valve body or you arent pressing the brake pedal hard enough which wont allow you to shift out of park. the pedal requires a good amount of pressure. as far as trans issues, you cant just walk into the dealer and request a new trans. on the newer cars, replacing a trans is a process and requires authorization from mercedes. and we cant just expect to get one by asking. alot of diagnostics has to be done first and all other options exhausted before asking for a trans. i have replaced maybe 5 trannies on the 722.9 vehicles. one was on a ml that had been in the shop over 6 times with tranny issues and the car was bought back. one was on an e class that was slipping. one on a s class that was slipping and recently on a brand new sl where the car was stalling due to the converter coming apart (had excessive metal in the pan). |