WTF.
I just installed new sway bar links and bushings so I went for a cruise to enjoy the non-rattles.
At 50mph on a smooth, straight, empty highway I go over a dip that I didn't even see and the truck quickly changed almost 1/2 a lane to the right.
Luckily I didn't over-correct but it was slightly concerning.

I do have a daystar 2.5 level kit thats 2 years old but this is the worst swerve I've had. There is one or two bumps in town that I have felt similar but not even severe.
I have brand new Michelin tires, brand new wheel bearings, newer a arms, new alignment.

Is this due to the spacer lift vs. taller spring/shock combo? Or is it panhard related?

I'll check out my dash cam footage tomorrow.

That sounds A LOT like a toe in/toe out issue. I'd go get an alignment!!!

Video doesn't look as bad, but it was just before a bridge transition.
Three potholes in a row with a slight dip that you can't see.
That would explain it more than anything. There are re-paved roads all over the city, plus my new tires and suspension, I was enjoying not feeling anything for a minute.

I don't have near as much as you, just Wheeler's t1/t12 with 5100s, but after driving with it for a year those types of potholes or dips at speed terrify me. I don't think I've ever been pushed 1/2 a lane over but I've hit some at 70mph that made my stomach jump up into my neck and always wondered what it was that was causing the biggest issue.

So it felt like 1/2 lane but was only maybe 2 feet. Still. That is enough to make a pucker.
I posted this and the video to Ohio DOT twitter and they replied right away. Wahoo!
Not sure if a twitter video link will work here

https://twitter.com/GabrielUtasi/sta...410661894?s=20

In solid axle trucks we talk a lot about caster angle and bump steer. In IFS trucks like our 4Runners the front suspension is where you need to look for stability. Some ideas:

bad front shocks. How old are your struts?
bad upper and lower control arm bushings / ball joints.
the above items if not correct will cause alignment issues.

tire pressure and quality tires

The shocks, struts and control arms are all 2 years old.
The Michelin tires and tie rods and wheel bearings are all good as of 1 month ago.
Fronts were the full replacement quick struts and rears are basic shocks.
Maybe I toasted the rears last year when I hauled 40 boxes of tile driving on the bump stops for 10 miles.

After I bought my 4runner I’d be driving on the highway and would get a weird pull to one side, similar to what yours did, even without any bumps. And definitely made my heart race a few times. Turns out my power steering fluid was trashed. Flushed that and never had another issue. Not sure how old your truck is but that could be another thing to check.

Great idea. It is pretty dark and gross. I've isolated most of my little clunks now and other than original CV axles, I'm good. The steering rack has slight moisture, but not concerning around the exit of each end.

I'm thinking of just removing the daystar lift anyhow. I like how it looks lifted, but I never got the upper control arms to make it really drive as tight as it did originally.