Curtis B. : Not knowing how new the GLC is, I will assume it has the electric solenoids at the transmssion control cover. Then it would have micro switches on the shift lever under the steering wheel. You will have three switches, a neutral, a forward and a reverse switch, all are wired so they activate the solenoids when you move the shifter. With both directions not working, it can be the neutral switch causeing problems or it can be related to your inching brake!
Curtis B. : The inching brake , activated by the left brake pedal, kicks transmission into neutral when brake is pressed. If it does not return to neutral, you get no f/r.
Curtis B. : Use a voltmeter or test light to see id the f/r solenoids are getting power when shifter is moved. If they are, problem is in the inching brake.
I am somewhat confused. I have the lever that selects forward and reverse. It is connected to a switching box on the right hand side of the steering wheel. From there, I cannot see where it goes, other than wires. I do not see three switches. So, I do not know what the inching brake is or the three switches.
Curtis B. : Just go to the transmission cover and check the solenoids for f/r . If they get power or you hear them click, they are good. That would leave the inching control.
Curtis B. : The inching control is controled by the left brake pedal. Look for a brake line from left brake, to the transmission cover.
I only have ONE brake pedal. Is the "transimission cover" the plastic cover that goes around the steering wheel?
Curtis B. : Your shifter may be a one piece lever and box, and may have to be replaced as a unit. Switches would be inside and not serviceable. But check for power to the solenoids and power to the shifter before replacing it!
Curtis B. : Ok, single brake will be same, but transmission cover is under the floor board. You have to remove the floor plate to see it.