f150 4x4 25k yr 2005just in the last week . when I start to pull away from a dead stop I here a grown from the rear of the truck not real loud and can;t tell which side , as you speed up it goes away . does not do it every time . any help idea appr jim.

 

if the vehicle has a locking or posi rear end clutches are going bad

 

rear brakes or the parking brake could be sticking

 

i Have a a 98 f150 4x4 and every time i hear that groaning sound coming from my rear my damn rear end gears blow days later.....iv gone through this 7 times...**** sucks. so hopefully for u it aint that