700R4 shifting problems

Who can help?
My 1988 700R4 wont shift right. Its a 1988 TPI V8 /700R4 with the original computer and wireing all put into my 65 Van.

It upshifts way too early including the TCC lock up.

I adjusted the kick down cable, It now takes longer to make the 1-2 shift but then almost emediatly makes the 2-3 shift and then TCC lock up all too soon.
The rear gear and tires are different then the donner car but not by much, Do I have to change something to compensate for that? Is the early up shifting a hydraulic control problem?

I think the VSS works , how accurate I'm not sure. My scanner reads out vehicle speed on a road test and looks generally accurate. (no opperating speedo at this time).


I also noticed the TCC wil engage while driving no matter what gear I have the shifter in. I know this because my TCC brake switch works so I can touch the brake pedal while driving to make the TCC disengage.

This trany does not have the vacuum switch, It has the mechanical cable to the throtle valve. I cannot see any evedance of it ever having the vacuum controll either in the donner car or the GM shop mannual.

It has the TCC solinoid, a brake peddal switch, a high gear switch, the original computer and a Vehicle speed sensor buffer from the donner car.

I am about to recheck all my wiring installation and would appreciate any comments.

M1D

The cable was exactly as it was from the donner car. I didn't have much chance to road test the donner so I don't know how it was before. I did reajust it like the book says, it changed in that it took longer for the 1-2 shift but then the 2-3 shifty followed by the TCC lock up came way too soon after.

Joyrde gave this link
http://www.transmissioncenter.net/700r4.htm

This is a must read for people with auto trany, and conversions now and being considered. Fantastik imfo for conversions.

I belive my VSS (speedo) gear is wrong. And the govenor might be sticky from sitting. I also think the "high gear" switch in the trany is done or the wire is shorted to ground. That last one would explane the TCC going into lock up no matter what gear I have the shifter in.

I'm just using the link above right now to determine what speedo gears I have and need.

M1D