Well, its been a while getting back to this. Got the garage finished but didn't get the heat in it yet so nothing done over the winter.
Did as Jerry suggested...put the truck in gear, lifted the drivers side rear tire off the ground while leaving the passenger side touching the ground, the tire spun freely. Did the same on the passenger side leaving the drivers side touching and the tire spun freely.
If its an axle how would I know which one it is, or could it be something else ?
Thanks
Dave