Bought my truck new in 08'. It's always had an ever-so-slight delay when shifting from 3rd to 4th, or maybe 4th to 5th gear, and the RPM's will raise slightly between gears during this shifting process. It hauls fine, figured its the nature and no big deal. I was pulling a small trailer (empty) the other day and and pressed the peddle down pretty good to merge with traffic. Did not floor it but mashed it pretty good. The delay between shifting shot the RPM's up to 3000 before it went to the next gear. It'll only do this for less than half a second. Truck has only 31,000 mi on it and I usually don't mash the peddle like I did that day. So, with being said, anything to worry about?

 

Sounds like tps,is your truck still under warrenty? If so, i would go back and let them look at this.

 

The throttle position sensor tells the tranny what to do, if it is bad the torque converter will unlock and lock at wrong time raising the rpm or shifting improperly

 

So if the TPS is faulty, can it be diagnosed for servicability? Do you adjust, recalibrate or swap the thing out? Whats it look like?