I am not really sure how to explain this in a non verbal way but I will do my best. For the better part of 3 months now when I come to a complete stop and then hit the gas to go again i get a strange eerrkk sound from the rear of my truck. It is louder if i hit the gas quick and even when very light it will do it just more quite. Checked the spare. ity locked in tight. Any other ideas?

 

Check out your diff, mine was doing the same thing before I changed gears. While swapping to some 3.90's i went ahead and rebuilt the limited slip with parts from Ford, there were some issues with the the clutch packs and lube from the factory lube. I still have a jug of the lube sitting at home, but I work in Iraq so I cant tell you what I used, im sure you can call your local Ford dealership and they will tell you what the recommend. You may be able to just swap fluid right now if you dont have the cash to have the clutch packs changed.