Well sorry it took so long to get back to everyone, been real busy around the house and haven't had time to tinker with the rear end untill recently...and good news!!! I changed out the fluid, putting in the Valvoline Synpower 140, within a week the noise was gone completely. But I had a new equally irritating squeeking sound coming from underneath the truck, along with a new, different metallic clicking sound. All I could say was "great!, what next?". Turns out I had a bad U-joint on the rear of the drive shaft. When I finally "BEAT" the caps off the u-joint nothing but 2 needle bearings and rusty dust came out of one...my friend who was helping, as well as learning, said "well there's your problem!". Obviously the grease had long dried up and had been grinding those needle bearings to dust for some time. So I guess had I never parked it, i never would have aquired the squeek, could've ended up pole-vaulting the truck down the interstate(seen it happen). All is well that ends well......so far. On to the next project...........