Originally Posted by
Scottrik
Nah...just a lot of little things that can be done to make your car work better.
The reason sanding diff rings helps is that when they're punched out they end up a bit bowed on one side and cupped on the other. You sand them by holding sandpaper on a very flat surface (a set up board, or I use a piece of tempered glass that I build cars on) and swirling the diff ring on it. You do both sides of each ring until the sanding marks are all the way across the faces from inner edge to outer edge. I like to use #400 until I have "cross-hatching" all the way across, then do a minute or two on #600 for a slightly smoother finish (no need to obsess here).
This can be done with your bare hands, though sanding through your finger tips makes 'em a bit sore for a day or two (done that plenty). IRS makes a diff ring sanding tool which is a machined aluminum holder with a raised ring that engages the inside of the diff ring. These were tooled up prior to the advent of "D"-rings but can be easily modified with a Dremel tool to make a straight side for the D. MUCH easier on your finger tips.
I use to do it that but now it's MUCH easier to just use the outer diff hub