Alright so I have been trying to track down the cause of this issue and i am coming up with no luck. At first I was terrified it was LBJ issues but i did the "jack each wheel up and grab at 3-9 and 6-12" thing and saw ZERO play at the 6-12 locations and a tiny tiny bit of movement at the 3-9 locations but nothing that seemed excessive.
Generally the issues begin in the 45 mph - 65 mph range. I can feel it in the steering wheel when it's starting to feel wobbly but it goes crazy when I'm braking at these speeds. If I drive on the highway for extended periods of time in the 75-80 speed the issue goes away all together. Generally the issue is most apparent in the first 15 mins of the drive. Also another thing I noted was that my left rotor felt really hot (like burn my fingers hot) after a drive while the right felt just warm.
Also I tested this in neutral and the issues still exist. So my theory as of this point is warped rotor? Could it cause vibes even when not braking?
Truck is an 01 bone stock btw.
Video of issue:
Going to rotate the tires this weekend to rule that out hopefully.