rotating squeak f150

I have a 97 f150 with 4.6 5speed 3door long bed with 150,000 miles on it. ok have a noise that is like a rotating squeak coming from the middle of the truck as far as i can tell. the sound only is loud in 1st,2nd,and3rd. gear. i have check everything i can think of and cant find it. its driving nuts with not far to go. please help,, thanks

Check the u joints in the rear driveshaft for signs of rust coming out and binding

that's what it was, the back u joint. Them are a pain in the butt with a 150,000 miles on it lol. thanks for the reply.