Issues towing my boat

I'm towing a flats boat and whenever I run at 2500 rpm after about 2 hours straight my rpm begins to jolt rapidly or slow rapidly and will not resume to 2500rpm. I'd say the weight of my boat is at most 2000lbs. I have a 2002 Tacoma prerunner v6 sr5 with a 3400 four cam 24. Has anyone else experienced this problem. Any idea why this is happening? How do other tacomas tow? Any info would help greatly.

 

So I take it your running cruise if your trying to "resume"
Is it searching for gears?
Any funny smells?
Never seen this or had reference to it in the shop.
Should almost tow as if it's almost not even there.
Some more info for us if you can think of it.
Did this just start happening?

 

I do not have cruise control and yes it is searching for gears. No funny smells or sign of overheating...

 

Are you leaving it in O/D the whole trip? Try turning it off next time. It will cost more gas, but be gentler on the tranny.

 

Is this happening during flat stretches or hills? If hills it's completly normal... just searching for a lower gear.

 

Yeah I tend to leave O/D on all the time. I will turn off next time and see if there's a difference. I have to tow it up to GA from Fort Lauderdale this week will see how it goes...it does it on hills but as well as flat strechtes.