Something really strange happened today... Leaving bi-Mart I noticed a ticking/squeaking/squeeling noise while accelerating. Random, figured I'd look into it when I got home. Couldn't find anything. Left for the park with the dogs, only 4 miles away through town. The squeaking is now even worse. I noticed it only really does it while under power, not much when coasting and not when idling. As I'm pulling into the park, my edge yells at me, telling me my transmission is at 240 degrees! Now I'm flipping out... Something's going on with the transmission. Does anyone have any clues as to what? First thing I did was check the fluid, full and clean.
The previous owner had it rebuilt and built 30k miles ago. Billet torque converter, shift kit, valve body, etc.

Got the truck home... Transmission ran at 195 degrees the whole 4 miles going as slow and easy on it as I could.
The noise could be described as a slight rattling, almost grinding at times, but definitely a high pitched squeak/squeal.
It seems to be shifting fine, everything feels normal, other than a god awful sound and really high transmission temps... Doing some searching, but I'm really having a hard time coming up with anything...

 

your going to have to drop the pan! or take it to a tranny shop for diagnosis! Could be something as simple as a TQ bolt backed out! Check those first!!!

 

Update.

Turns out the sound wasn't coming from the transmission, but actually the rear axle, particularly the driveline/pinion area... Not sure what could be causing this either.



And, theres still the issue of the transmission randomly overheating and now running hot... Any input would be appreciated!
With the tires off the ground, it does take a bit of force to get them to move by hand... But like I said before I can't tell anything different when driving the truck, it doesn't feel like it has any extra "resistance" that would be causing the transmission to work harder and overheat, or anything of the sort.

 

Bad TQ or Pump will do the overheating as well as a front cooler with a stuck flow valve.
As far as the noise check your brakes apply your brakes see if it goes away. Check your pads and rotors.
If not that pull the rear cover and look inside good reason to change the gear oil!