Pete K - you have given me some pretty good advice about my shakey 700R4. I have not yet dropped the pan to swap out the lock up selonoid, but I am getting ready to. I did some more troubleshooting and I'd like to get some feedback (from everyone) before I open the tranny up.

Here's the scoop - Tranny was rebuilt but never worked 100%. At first, there was a kick down issue - it wouldn't kick down at all. Brought it back to the tranny shop and they told me it was the cable. They put a new one in and it did the same thing. Brought it back again and they did something that made it kick down from OD to 2nd, but still wouldn't kick down from 2 to 1. THEN, it developed this shake in OD at low RPM. I thought maybe it was the 4 prong clip for the lock up because it was damaged when I pulled the engine & tranny. I replaced the connector and it got worse - now vibrates in 3rd and OD.

I unplugged the connector to trouble shoot, and the tranny works fine - kicks down like it should, no vibration.

The vaccuum is all out of whack on the car. I eliminated all of the pollution crap. The car runs excellent. Is there some sort of vaccuum switch or selonoid on my 87 that could be causing this. If so, why did it come on gradually? I would think if it was vaccuum, it would have done it from the get go. Also, is there some selonoid by the battery that I can change? Can anyone tell me how to identify it? I am trying to do everything I can before I open the tranny.

 

The vacuum will have no effect on the trans. 84-93 cars use a tv cable to tell the trans where the throttle is. Old turbo 350's used vacuum ours do not. When the trans was rebuilt,I presume that they installed a fresh remanufactured torque converter? If so, and the problem occured immediately after the rebuild, I would suspect a poor quality torque converter. Typically if a solenoid or pressure switch is bad, it results in no lock up at all. If you are going to drop the pan and start swapping parts, I would suggest you check them. Lock up solenoid should ohm check at 18-25 ohms. Pressure switches are either normally open, or normally closed. Give me the year of your car and I can tell you what "should" be in the pan.
There is more to lock up than the solenoid. The other parts are
Wiring harness
Pressure switch(s)
Temp switch(later years)
ecm signal
torque converter
lock up valve assembly.
As far as the poor shift quality, that almost always points to tv system. I would strongly advise pressure testing the trans to assure correct tv pressures. Typically they are approx 50 psi on the low side and 150 psi on the high side. Consult the manual for your exact year and model trans. The code is stamped in the pan rail flange on the pass side.

 

My vette is an 87. The torque converter had the word "balanced" stamped on it. Had the kick down issue immediately, but the shutter started shortly after. The tranny shop was run by a clown....they broke my gas pedal while it was there. I'll probably contact you to get a reman converter that you trust, but I want to be certain that is the problem.

 

I agree. Everything lock up related(except for the torque converter) can be checked without pulling the trans. A scanner will show if the computer is commanding the lock up, dropping the pan will allow for a full inspection and test of the wiring, pressure switches, solenoid and lock up valve. Symptoms point toward the converter, but don't swap it until you are pretty sure it is the problem.