1999 C1500 Suburban "Catch" in front end

[shultzee13]

Guys,

I have had the entire front end of this suburban rebuilt with all Moog parts. Even before I did that, I have always had a "catch" in the front end. Something slips when the road curves and I turn the wheel slightly. It doesn't do it every time, but when it does it's kinda scary. For a split second I'm kinda nervous. Any ideas what this could be?

It must be something I didn't replace, but you name it and it's been replaced on this front end. Shocks, upper/lower ball joints, tie rods, pittman arms.

Something is slipping.
Thanks.