Lost high gear in 1987 190D
 

My sons car was working fine when he parked it--next time he drove it it would seem to go to nuetral at 35 MPH, when it should shift to high gear. This is an automatic trans. I see that #1 fuse is for the transmission solenoid. Might this be my problem? Where is the solenoid? Thanks for any help.

Start with a fluid and filter change, filter's possibly clogged reducing pressure.

i think fuse is for kick down system when you floor the car.the trannys are mechanical.solenoid is on back of tranny.

The first and easiest thing to do is check that the floor mat is in the proper position and not adversely affecting the kick down switch on the firewall behind the accelerator pedal!

If the kickdown switch or solenoid is stuck, it should stay in 3rd until around 4600rpm, and then shift to 4th. It will not go out of gear like it's in neutral.

Most every time I've heard of this happening it is the same symptom as my E320 had. Mine was "test driven" by a potential buyer, who felt a need to run it flat-out, which it wasn't used to, and the high flow in the transmission finished filtering what was laying dormant in the pan, clogging the filter and causing low control pressure after any mid-high rpm use. Sometimes better for a short time after being parked for a while.

Anyway, several of us have been "lucky" by changing the fluid and filter, and having the symptom cease.

If you don't know the age of the fluid and filter in your transmission, or if it was changed last by a "flush" method, or if someone has recently driven the car at high RPMs, I strongly suggest a proper change of fluids and filter (pan and torque converter drain).

Thanks
 

I'll try the fluid change. How do you drain the torque convrtor?

There is a drain plug, turn the motor clockwise when you are standing in front of the car looking at motor. You will see the plug, have someone turn the motor by hand while you look for the plug.