I have a 97'f-250 LD when I stop at a stop sign and make a turn the back end starts to hop when I give it some gas It has new u-joints changed the fluid in the rearend and put in the friction modifier the only other thing that I can think of is that the clutches in the rearend are junk any more ideas or help

 

Welcome to FTE bubbasdavid! It could be that the clutches are shot. What about worn out shock absorbers? Good luck!

 

if it only does it when you turn, then it is the clutch trying to slip. if you put in PLENTY of friction modifier, then the problem is the clutch. personally i would add another tube of modifier first, and slowly drive in a big circle to work it in.

 

when you changed the oill, you had to have the rear cover off? what did things look like, how much crud laying on the bottom?