I did a change and put in a limited slip. I got a good contact patch on the drive side, but I struggled to get anything to show on coast side. I decided to button everything up and see what I get. Drive side is completely quiet. Coast side whines over 20 mph.

Installed is: new diff, new ring gear, new bearings and caps. new axle bearings, new axle seals. Didn't touch the pinion.

 

Aren't ring and pinion supposed to be matched to each other? I have always replaced them together......

 

Yep, I think this is a bad advice issue from a local mechanic. I was going to have him do it, then he ghosted me when I was trying to schedule. Before that, he asked why I'm changing the pinion if it isn't bad. He knew I put a new ring on.

I have it partially apart now. I had to order beefier snap ring pliers for the diff housing snap ring on that Eaton.