Just bought 1984 300sd with 245000 miles for $900...great car...tranny will only kickdown below 40mph and is not a function of microswitch under pedal...over 40 it will not kickdown at all.
Tried adjusting cable...was able to improve shiftpoints but still no kickdown. Is this solely the function of the solenoid or could I adjust the cable a bit tighter? I am afraid to overtighten.
How can I determine if the switch and/or solenoid are functioning?

Thanks in advance...

I adjusted this cable this past weekend and the difference was amazing. Mine will kick down when floored as long as I'm under 60mph, then the rpms will whip up to 4K before shifting.

I have the same year car. You are looking for a cable coming up from firewall side (and runs down towards the tranny) that has a white plastic threaded end right where it attached to the throttle linkage on top of the valve cover.

What is hard to explain is on that once you locate the throttle arm where that cable connects; there should be another arm that acts like a “stop” so that the upper arm can only move backward so much towards the rear of the car. To adjust the cable simply turn the white plastic end piece on that cable that I mentioned before until you pull the upper arm back towards the stop. It should just rest on the stop with no tension (wiggle it - it should not be so tight that there is really a lot of pressure on the stop).

I heard if you over tighten the cable the car will burn through the 1-2 shifts too fast.

That might not be the most eloquent explanation, but I'm at work (not near the car) and I'm doing this from memory...

It's a 30 second adjustment.

__________________
~shell
As of 2/2010:
2001 CLK55 0o\=*=/o0
13.6 @ 106mph
10K mi
1984 300SD
260K mi and going and going...
97 S600
46K miles
1991 Sentra SE-R (extremely dorked with)
www.se-r.net

Thanks so much for your reply...I was beginning to wonder if newbies were ignored or if my post had breached some point of etiquette. I will follow your guide and report back.

Thank you.

Jason