Steering gear strange behavior.

I just replaced my steering gear on my ’91 (4.0L). The old box was leaking at the input shaft seal. I found a relatively low mileage unit from a 2000.
While I had the draglink disconnected, I started bleeding the system. I followed the FSM procedure.

After the bleeding process, I noticed the gear box had a strong left “pull”. Basically, I have to hold the steering wheel so it doesn’t rotate left on its own (drag link disconnected).
After assembling everything, I took the car for a road test. The strange left turn behavior continued. I definitely feel more resistance turning right. Left turns are almost effortless.

I think this is caused by a defective steering gear. Before replacing it again, I would like to know if this strange behavior can be caused by some air still trapped in the system.
TIA.

I rebuild a lot of boxes. I have only seen that behavior in vehicles with actual linkage problems or severe alignment issues.

It never hurts to burp the system. Put the front up on jack stands, Start the engine and slowly turn the wheels from lock to lock multiple times. Do not stall it against the limits.

For it to be harder from left to right, there either has to be some crap stuck in one of the orifices in the front end of the box, or maybe the bearing is so shot that the rack and pinion setup is binding.

I would hate to say how many boxes I have gotten that someone has tried to rebuild and totally screwed up how things go back together.

This “new” box does not appear to have been rebuilt or opened. I definitely feel it is an internal problem. As you mentioned, maybe some dirt in one of the orifices. What I can add is that I can also feel a slight jerk to the left on the steering wheel when I start the engine.

The problem started halfway through the first bleeding process, while I had the front on the jack stands and the drag link disconnected. Alignment and linkage did not come into play.

I will try to bleed it again (the third time). If it doesn’t eliminate the problem, I will have to install a different box. Thank you for your help.

The spool valve that controls the left/ right assist is located in the box, probably has some debris in it. Sounds like time for another one.