Re: any ideas on my screwy steering ?
OK, now that you are sure that it's not slipping - I hope you really did take the Pitman arm off - as you cannot see the shaft's relationship to the arm slipping - the nut covers it. It won't slip much at first.
What happens if the splines are not cut right it works for awhile - then all of a sudden the arm cracks and it slips completely, leading to total loss of control. I wish now I had saved one to show you that I recently replaced.
If you still have the old arm you can see the wider cuts to help align it. Some of the aftermarket arms around don't have the wider cuts. You have to make them yourself with a file or grinder.
Moving on -
If the trackbar and the draglink aren't close to parallel - it will cause bumpsteer - when the body squishes down a little from a bump the wheels try to turn, then on rebound they turn the other way. So going down a bumpy road you are all over the place. Having then parallel helps minimize that.
But - by your description that's not so much the case - right? You are feeling it more "sensitive" turning one way than the other? And your first post indicated it's not always the same. The inconsistency it what's scary. If everything is tight, it should always be the same.
I'm wondering about the centering now.
Try something - Turn the steering wheel from end to end, counting the number of turns. Then turn it back one half of that - that should find the "center" of travel. Leave it right there. The steering wheel should be straight, but in any case leave it there for now.
Are the wheels pointing straight ahead? They should be now.
Go take a look at the Pitman arm. It should be pointing parallel with the body - straight back, not angled to the side.
The Pitman Arm swings through an arc - it should be starting in the middle of that arc at center. Sometimes if the Pitman is not put on "centered" when the wheels are "centered" it can seem like turning one way is easier, or more sensitive, than the other way. (Your complaint?)
The other possibility - did you replace the control arms? If one side positions the axle slightly farther ahead than the other side - like one side is adjusted longer than the other (either front or rear arms), the axles are no longer parallel. That too can make it seem like it turns one way easier than the other.
You've probably seen a vehicle ahead of you that looks like it's going slightly sideways as it travels down the road, called doglegging or crabbing. That's where front to rear axles are not parallel.
Use a long stick, place it against the axle tubes front to rear axle just inside of the brakes. Measure one side, then the other to compare. More than 1/4" difference side to side can cause this.
It's a common problem when installing new arms - but you can measure it yourself without alignment equipment.
Also center the wheels - stand in front or back - look to see that the axles are centered. Sometimes you get one farther to one side than the other (trackbar length adjustment - but as long as they are parallel you normally won't "feel" it. It just looks silly unless it's waaaay off.
Trying it with the steering damper disconnected will eliminate that as a cause.
Let us know what you find.