hello all. i've noticed that i seem to have a little slip in between 2nd and 3rd. it seems to take a little longer to shift as i'll feel it start to shift and then complete the shift maybe 1/4 of a second later instead of shifting right in instantly. i do have mud terrain tires on the truck for the winter weather but the tires are the same size(245/75/r16). could the really aggressive tread cause this? it didn't seem have this when the other uniroyal A/T tires were on the truck, unless it was less noticeable. trans fluid is red as it should be and doesn't smell "burnt". no codes. any suggestions? it only does it when i accelerate slowly it seems. if i hammer it from a stop like if getting on the highway it pops from 2nd to 3rd perfectly normal. thats why i don't think its a trans issue. if the trans was slipping wouldn't it do it all the time?

I don't think mud terrain tires have any affect on how fast the valves shift within the vallve body. I do think you will feel the difference in the hardness of the shift.
What you need is a Tech II to tell you how fast or slow the shifting is taking place. I don't believe the Tech II can tell you how fast it can go from second into third electronically.
The best I can offer you is to retrieve codes. Remember the codes that you are retrieving, I believe are active and not historic, again this is where the Tech II shines.
You can always theck the resistance on the 2-3 shifting solenoid. Check the sticky for the specs. Checking the resistance If the resistance is getting high then the solenoid is not working as fast as it should. (possible) not a definite.
You can buy 2-3 shifting and drop the pan and with a star screwdriver replace it but there are no guarantees because it might be a valve matter. The shifting solenoid simply redirects fluid pressure and actuated the 3rd gear valve. It's worth a try. They are cheap enough.

My best best is to take it to a reputable shop and get the total readout with a techII. It will tell you the whole story.