transmission Woes???

[GFreshour]

I have driven my 06 4x4 like a little old lady, always followed maintenance schedules and read the owners manul like a bible. I sometimes tow a 15k 5th wheel, at moderate speeds (63 mph) and always use the tow/haul setting. I do have a jake brake. After my last 5700 mile trip the transmission seems to shift most harshly, a real head jerker. Am I a candidate for transmission replacement/upgrade?? (53k on truck)

 

[cerberusiam]

Trans temp gauge? These transmissions will start shifting hard and early when the temps spike. Could be a number of things causing it but temp is the first place to start.