I'm sure @2001LC will follow up with a more technical post at some point (Paul is still trying to understand the root issue as I understand it), but he replaced the VGRS actuator and it appears to have fixed the issue. Just wanted to follow up.
Thanks guys. I do have the old set of wheels and tires to try and will do that. I think it's also reasonable to check the alignment (and I'm planning on it), but what's so odd is that it gets progressively worse as you drive the truck longer. First ~5min it drives straight as an arrow then...
I do have SPC uppers and I suppose a cam could have slipped, but I thought death wobble wasn’t really a thing on IFS. Caster was set to about 3.1 on each side.
I will preface this by stating that this is not an issue of loose wheel bearings trigging ABS system to grab a tire. This one has @2001LC and I somewhat stumped. I've also gone through most of the VGRS related threads and found good info to inform investigation but no conclusion yet. Paul has...