Front end messed up after steering knuckle swap w123 -> w126

[Zacharias]

Swapped out steering knuckles from my '85 w123, non-abs, for a set from a 1985 w126 with ABS today, and also replaced my front rotors. Now that it's bolted back together it's driving awful. Steering feels very odd, like a sloppy steering box (very light and no desire to self-center), and when the wheel is turned to go around a corner it wants to pull hard to that side.

Background: Point of this was originally to buy the second set of knuckles to have new lower balljoints pressed in and ready to go, to avoid taking the car off the road during the balljoint change. However, when my friend parted out the w126 that was to serve as the knuckle donor, he discovered the balljoints looked nearly new so I decided to just stick with them and install the knuckle as-is.

I did move the w123 backing plates over to the w126 spindle, as the ABS ones are quite different.

It has been a long day in the sun and I may be buzzed enough to have missed something. I am going to start pulling it apart again tomorrow but if someone has input based on the symptoms, it will be most appreciated.

These knuckles are supposed to be a direct swap item, however right now if I had to guess, I would say that the car feels like it has tierods that are mightily out of whack (feels a bit like a car I bought once that had hit a curb hard and bent the tierod and center link).