I can vouch for this (over tightening). I did the same thing on my F-150 gear box. I had to back the adjustment screw out a couple of turns to get it to loosen up and allow the wheels to center automatically and with ease. There's a small window of it being "just right" (in my case anyway).
Just making a point it could happen. and believe it or not by over tightning the afore mention items you do in fact deform the ball causing rapid wear. Guys who gun'em and run'em find this out early on in thier mechanic career.
I have taken many classes pertaining to Front end wear. If you over tighten anything it effects the entire component.Tapered or not. The taper lessens this effect of course but does not elminate it entirely. You are talking machined parts. Thousands of an inch make all the difference. It does distort. I have seen this first hand. Do this test. Take a Ball joint cut it apart. Install the ball joint shaft into the correct spindle. Then tighten to correct manufacture specs. Take a suitable micrometer and take several measurements of the ball at varios points. Then Start over tightning and take readings in step. You will find there is a difference. I wouldn't have believed it either until a MOOG training rep showed me. I no longer gun em and run em as a result.
