I have an 86 Z28 with a de-computerized 383 in it. The tranny is a rebuilt 700R4 (The original tranny grenaded) with a lockup torque convertor and a 2500RPM stall, and a Eaton limited-slip posi rearend with 3.73s.

For the past little while, the convertor has stopped locking up. It used to always lock at around 40+mph when I was in 4th, but it doesn't lock at all anymore.

Is there a limit to how much torque a locked convertor can take? Could it be a fluid level issue or something like that? (I did check the level and it looked OK).

Comments or suggestions?

 

It won't lock up without a computer to tell it to.

If you have a manual switch or a vacuum switch or a 4th gear switch to lock it and now it isn't working, well either the switch is bad or the solenoid is bad.

You'd have more problems than no lock-up if you were low on fluid.

 

How can I tell if it's a manual switch or a vacuum switch? It was locking before, and then it started not doing it every once in a while, now it doesn't at all.

Where would I find those switches?