Steering slop?

Looking for input on an issue I'm having. Truck is a 2007 Tacoma regular cab 4x4 on 37's. I have steering slopes i can't seem to get rid of. I've gone through the front end, and have narrowed it down to something in the steering(duh huh).

I've replaced the following parts over the last year:
Upper uniballs
Lower balljoints
Wheel bearings
Oem cv axles
Upper AND lower steering shaft
Oem steering rack with poly bushings
New tie rod ends

Is there something I'm missing in the steering side of things? The knuckles are tight, all of the slop seems to be when I work the wheel back and forth while jacked up. All grease points have been maintained as I'm ocd with maintenance. I would really like to fix this if I can, but is this just a symptom of too much tire?

 

Do you have an alignment printout?

 

I could probably find it. Alignment was spot on, save for the caster which I specifically requested to move forward, but even then that is barely out of spec. Truck tracks straight, other than a little vagueness due to caster and the aforementioned slop.

 

Did the slop show up after you went to 37" tires?

 

The slop was there when I had 35's as well. When I grab the wheel/tire and work it back and forth it appears there is slop somewhere in the steering column, but I've replaced both upper and lower shafts with no effect.

 

Recheck the lower steering shaft. My truck, on stock tires and highway use, will eat those lower shafts up. Idk why.

 

I would check to make sure your steering rack isn't moving.