When my truck up shifts to second gear from first gear sometimes it feels like it shifts back into first again, it's either that or maybe it's like a half shift. Any ideas on what might cause this? It doesn't do it all the time, just occasionally. It does it no matter how hard I am mashing the throttle, it even does it when I try to keep the egg under the accelerator from making an egg salad on my floor boards. 2 - 3 - 4 - O/D has no problems with shifting.

I'm not too up to date on all these new fangled transmissions, so I am pretty lost here.

 

Do a fluid and filter change, and adjust your bands. I think there is a DIY in the faq section for this.

While you are in there, check the governor pressure solenoid, and see if its screeens aren't sludged up.

 

Oddly, I just changed the tires back to the stock size today and now it's shifting perfectly fine, brakes are working better, and it's got the acceleration back that it used to have ... do tires really make that big of a difference on these trucks?

 

MOST CERTAINLY!

the larger the tire over stock, the more effect it will have.