This is all interesting, (LS400, 91, 235,500 miles) I experience this wobble too but only if one of two things are going on -first- I cruse in 1st gear around 2,500 to 3,000 RPM 2nd or if I am traveling on a hwy for more then 20 min and at a constant speed of 85 mph or 2,200ish RPM. Unfortunately I have never checked the temp of my wheels. I was under the impression mine was a tranny issue suz the RPM combined with temp of tranny fluid. But my problem might entirely different from yours. Cuz when I check the steering wheel (letting go) at 85 mph. I drive straight (no lie for 1/5 mile+ until curve) but I get no vibration in the (free) steering wheel but feel it through the floor and set. So I guess what I’m asking you is if you just drive in 1st and still experience the same issues with your car, and is it RPM/Speed/Time related with your problem?
Don’t mean to thread jack but if anyone else has my problem or solution could you hit me up