Steering wheel jerking on bumps

[4OYOTER]

I have 5100s all around at 1.75" with stock springs and cornfed 1" spacer in rear. I have had issues getting my alignment in spec ever since. (I account this to incompetent techs) After my most recent alignment everything is "within spec", but I can really notice my steering wheel wants to jerk left or right when hitting bumps on the highway above 60 MPH.

I have to keep a very tight grip on the steering wheel whenever there are bumps in the road on the highway. I don't notice the issue below 60mph. Could this be because my caster is on the lower side? Would new UCAs resolve this? Or is it just a trait of my suspension setup? Or maybe something is worn or loose? I only have 65k miles, so I doubt a worn component. And I have checked torque on all obviously suspension bolts.

Here is my most recent alignment print out .

 

[05Rrunner]

You need more caster

 

[T4RZAN]

^^^^ The caster should be as close to 4.0 as possible. Not sure if you know what caster is but it essentially is how far forward the center of the wheels are. So getting closer to 4.0 will allow for a longer wheelbase meaning a more stable ride. Not sure if that will entirely "fix" your issue but I would definitely agree the caster should be higher.

 

[4OYOTER]

Thanks for the replies. I've heard of low caster causing wandering, but not an actual jerk of the steering wheel. I already knew some UCAs would be a good idea, sounds like I should get them sooner than later.