Okay, here's the deal. I bought an 84 T/A with what appears to be a mid-eighties 350 Chevrolet engine. Apparently, someone changed the transmission as well. The fluid pan of the tranny looks like a TH700. When I tried to attach the speedo cable, I discovered that the sensor on the tranny is electrical. On closer inspection, I noticed that most all of the wiring harness was not attached. The tranny doesn't slip, but the shifting is erratic and unpredictable. Also it seems like it doesn't go into overdrive.

My question is; what all needs to be done (short of a transmission change) to get this thing operating correctly. And how do I go about doing it.

Thanks

 

Well first you need to find the numbers on the transmission, you need to know if its a th350 or a 700-r4, the Th350 is three gears, no overdrive, the 700-r4 has over drive but only if the TV cable is adjusted correctly.
So is your car computer controlled?
Is it a 350 or 700?
is the TV cable adjusted correctly?
Did you even reattach it?

 

Well, the engine is not computer controlled, that I do know. Strictly mechanical. Who knows about the transmission . . . . that's anyone's guess. I am mainly going on the fact that the transmission pan is the exact size and shape of a TH700.

The TV cable is the kick down cable? Right? It is reattached and I believe correctly adjusted.

 

Well thats the problem, if its a carbed motor, the 700-r4 is computer controled, there i a kit you can get TCI that will eleminate the issue. There has to be vacume and a switch to make ground. I burned up a 700-r4 when i did my 350 swap with a Carb....

here is the link to summit
http://www.summitracing.com/search/?...ock%20Up&dds=1
i used the top one, worked fine till someone gave me a th350

 

Thanks!!! I'll give this a try.

One other quick question: Why would the speedo sender be electrical with a cabled speedo? I'm very curious as to what kinda transmission this is. Possibly an 4L60E?

 

its possible just pull the numbers off it there is a plate, I believe its on the side of the dip stick, although I could be wrong but you cant miss it and runt he mnumbers you will know just what it is, you can easily get a gear drive to put into the electronic hole, at least I believe that is what I did...

 

700r4s are NOT computer controlled. They work perfectly fine behind carbed motors.

I would bet improper TV cable adjustment is the #1 killer of 700r4s. You do not have to run that kit from TCI. That is purely for lockup in overdrive/drive. It has nothing to do with the regular function of the transmission or overdrive.

4l60E is a different story, they are computer controlled.

 

yeah but with everything mechanical and the computer isnt there to lock up the torque converter then that will strss the trans causing it to fail due to over heating the fluid and buring the clutches. but i might be wrong i cant remember

 

if this is true im wrong thinking my 86 has a 700 r4??? cause it has a carb?? ^_^ for being mechanically challenged