2017 Thud on Highway

I am currently taking my 2017 TRD Sport on a road trip and I experienced a very weird and concerning issue. I was driving at highway speeds ~65 or so and I went to pass a semi. It's a two lane road so naturally I turn on ECT and start the pass. Well in the midst of it I had it floored and I noticed when it went to go shift at redline I experienced a thud as if I hit something, the tires chirped and I let off the gas because it scared the shit out of me. The whole truck lurched backwards. Only thing I've done to it is the OVTune 91 performance. It's the auto transmission with 25k on the clock. Anyone have an idea as to what this could be? I'm going to be working her hard the next few days pulling a trailer over 700 miles.

 

I get that thud when I accelerated to pass but suddenly have no need to then lay off. Basically telling the truck to switch gears then not needing to. I always wondered what it was too.

 

Did you stop and look for the body...?

 

Doing so is admission of guilt...

 

I hate to bump this thread, but I can’t find anywhere on the internet that references this issue, I’ve felt this a few times, both happened on the 3rd-4th shift. There is no reason it should chirp the tires at 70-90 mph. When it happened I was running the same tune at WOT. The second time it happened, it wouldn’t shift for 2-3 seconds and then if shifted so hard it felt I got rear ended.

 

Exactly what it felt like for me. Felt the tires chirp mid shift, felt like I got rear ended or lost my tranny. I don't think I can accurately describe how harsh it was. Hasn't happened since though