Gear box or pump?

[pelky350]

Once a couple week and ago my steering seemed to not return to center while driving, last night it did this to my again on a corner and caught m off guard. Like hap pier assist while turning and then when straightening out it didn't come back to center. Box is from salvage yard a few years ago when previous box lost seal. Pump is old and I ran it out of fluid at least 20x during this leak from the box. It maybe both. Other note I did top it off with some Lucas power steering fluid product a month or so ago not the thick stop leak stuff just a additive I got on sale one day

 

[Thewespaul]

Not returning to center is your box

 

[chris142]

Not returning to center is your box

Or a ball joint or a ujoint

 

[pelky350]

Both king pins have been replaced in past two years, and steering linkage checks out with almost no play, actually it appears that my gear box is the only play I have in my steering. Power steering additive wouldn't have anything to do with this by chance would it?