I have an 87 iroc with a 700r4. I bought the car recently and the trans had supposedly been rebuilt, I saw a tag on the top of the bell housing from some remanufacturer when I had the distributer out and it operates fine so I guess I have no reason to doubt it. My question is about the lock up converter, it only locks up in OD and it locks up immediatly after the 3-4 shift no matter what the load. Also it will not unlock if you let off the gas and hit the brake, it nearly kills the engine when braking to a stop before it downshifts to 3rd if you leave the shifter in OD. Does anyone know how to get it back to normal or at least how to get it to unlock when you hit the brakes. Many thanks to anyone with replies

 

Anybody? Please this is driving me insane.

 

Okay let me take a stab at this. I think the rebuilder wired the TCC to come on only in 4th gear. You use a pressure switch on the end of the 3-4 shift valve train in the valve body that is tied into the TCC solenoid. The wire that goes to the pressure switch has 12 volts wired to it.When the trans goes into fourth gear the fluid pressure on the switch makes the circuit and the TCC comes on. That is probably why it takes so long to release on a downshift. I think that the TCC is wired directly and the brake switch is no longer part of the circuit. I think it might be possible to get a 700R4 to lock up the TCC hydraulically but I've never seen it done. As for undoing it and go back to normal you have to find out how the trans is set up. I dont think that it would take a whole lot to do it.

 

If the unit was rebuilt, it might have a checkball in the TCC solenoid snout that when it locks up it will keep it locked up, until you grab the lever and bring it to 3rd gear. If this was done, it can be removed.

 

both scenarios look possible, but i have seen the latter more often.

 

Guys thanks for the insight. That problem coupled with a low rpm surge on deceleration keeps me from letting my wife drive the car.