Steering Wheel Slipping

[Overkitty]

We recently replaced the engine and transmission (along with a few smaller things that were in bad shape) of my 92 SC400. It is now exhibiting an interesting problem with the steering. From neutral position to about 45 degrees either way the steering wheel seems to slip. Once I hit a certain point, about 45 degrees, the steering wheel catches and starts turning the wheels properly. The problem is most noticeable on long highway turns where you turn the wheel much slower compared to street turns. There it is most dangerous as the wheels don't turn properly for the first few moments cause me to go straight into the turn. To counter this effect, I have to jerk the steering wheel past that point but that in turn jerks the wheels a bit which is a bit unsafe. Another result is that after I turn left, the steering wheel is cocked to the left about 45 degrees when the wheels are straight. Like wise, if turning right the steering wheel is cocked right. I hope I am explaining the problem competently enough. Before the engine and transmission replacement, which was all done by us, the alignment was off a bit but this problem didn't exist so I would assume we did something wrong. Regretfully my knowledge of the power steering system is fairly basic. We did replace the pump before the engine and transmission where changed. The fluid is fine and we made sure to bleed it properly.

Any help is appreciated! Thanks!