1993 GMC Jimmy automatic transmissions

I have a 1993 S-15 GMC Jimmy, 4-wheel drive, 4.3 Vortech. i recently replaced the motor and now the transmission won’t turn when its hooked up to the flywheel, but when the torque converter is unhooked the engine will turn. what could be the problem

Did you seat the torque converter al the way into the transmission? The torque converter on this 700R4 transmission will seat onto 3 shafts to properly seat. The first is the intermediate drive shaft, then the primary driveshaft, and finally the transmission pump drive. If it is not completely seated, it will bind up and not turn.

When you first installed the converter, did you feel it seat fully into the transmission?? Its very easy to install the converter improperly where the converter hub does not make contact with the tangs on the pump. The end result is destruction of the pump. Time to get on your back, reach up in there and move the converter around a little. You might end up having to pull it again.


Do you think the new motor could have a bushing in the crank end as if it was set up for a manual trans?