300D Still has fast Upshift Problem= HELP
 

I appreciate all who have read this...Still trying to solve the trouble and have nowhere to look..

In trying to solve the problem that this 84' 300D turbo upshifts through all 4 gears into drive at 20mph, the following process was followed:

1.) checked and adjusted throtle pressure cable
2.) checked vac supply to vac modulator
3.) checked modulator, itself
4.) removed valve body and checked throttle pressure valve for sticking or binding
5.) checked govenor assembly for sticking or binding
6.) checked trans. pump pressure (within spec.)


This 300D will also NOT downshift via kickdown switch.

1.) checked switch under pedal
2.) checked circut to solenoid
3.) checked solenoid itself

When you manually shift this trans., it has a nice firm shift. Doesn't slip and upshifts according to shifter position. In the process, the trans filter was changed and the contents of the pan inspected. There was virtually no material in the bottom of the pan and the fluid was clean and not scorched.

Anyone have any thoughts or suggestions?

Thanks Again....Frank

Frank - I'm relatively new to this forum. 1985 300TDT wagon (California) Same problem - upshifts to fourth before 20 mph. Had fluid, filter, modulator, changed. Valve body removed and checked. Bowden cable is ok. Was told that it could be governor. Did not check vacuum yet. Have you figured out your problem, fixed it yet? Was told that rebuild would be way to go if I drop trans to check and/or fix governor.

Sounds like the bowden cable is too tight. Try relaxing the tension slightly and see if this helps.

Haasman

Haasman - The bowden cable does not change anything (in my case) I've tried to adjust - with very small adjustments both ways all the way to the extreme - with no change. Am I missing something here with this cable? Thanks.

Frank

Does your car have the shifting vacuum control block on top of the engine's valve cover? I can't remember if the 300D turbo has the same setup as the 240D. If it does, it could be that the two little black valves are worn out. This cured a number of shift ills on the 240D I had.

I will search the posts and see what else I can find.

Keep us posted,

Haasman

Haasman - The control coming off the bowden cable is a switch -a 2 position by the looks of the wiring. A cam turns to engage it as throttle is increased - there are 2 "clicks" as cam turns . Thanks.