Shaking

[RedFX4]

Hi,

Just go some 33" Toyo M/Ts put on yesterday. Today I took the truck out for a highway drive then bombed around town (which entails lots of steep grades). It was fairly warm out and the tranny temps started to get up there, around 185F, CHT 210-212. Anyways, when I went to back into a parking stall the truck felt like it was grabbing and the let loose. Kind of a subtle lurching. Last time I felt something similar was when the transfer case fluid's viscosity went out of whack. You could visibly see the front end rocking side to side.

The truck was running 91 octane on the 93 canned tune with the timing backed off 0.5 degrees.

What could have caused this? I let it sit and put it back to stock before starting it again and all felt fine? Haven't put it back on the canned tune. Is this the stumble/miss/hesitation that people talk about?

My theory is the rear diff or tranny fluid lost too much viscosity at the higher temps so any friction plates may have been grabbing, or there is a motor issue with the canned tune and the bigger and much heavier tires and heavy load?

Let me know if I should be posting in a different forum.

Thanks