Just wondernig how much I should add to my ls rear end?

 

Which rear end? When I did the 9 3/4 in my Expd, the techs at the Ford place recommended 2 bottles.

 

For the 8.8 and the 9.75 diffs 1 bottle is recomended and if you still have any chatter to add another bottle.

I added a larger diff cover and more oil so I too added two bottles right out of the gate.

 

My ex 2000 f150scab 5.4L 4x4 with 9.75" traction lok started popping and snapping on the corners at about 80k miles and I changed the fluid and put one bottle of modifier in. It acted the same. Then I found out about a TSB that recommended the fix of replacing the clutch pack and reducing the shim preload by 0.010". The ford parts guy told me to just put in another bottle of friction modifier. I did and it worked.