Originally Posted by stang93mustang View Post
Not saying I have an answer but does it do this when you turn by hand?
If it only does it while under pressure then my guess would be something with the lash. Just my thought. Under pressure the drive shaft is pushing the pinion forward some.
Just found this: http://www.drivetrain.com/parts_cata...tructions.html
Maybe you don't have enough lash.