...new 8 3/4 ...sounds kind of like cast metal scraping ...it's mostly speed based ...has a horrible vibration to it at highway speeds ..."I took a look at the driveshaft while it was running and it doesn't look like it's turning around center" (explain please) ...I put brand new U joints in it a few weeks ago ...guessing that maybe it's a pinion issue (have you checked pinion angle?) ...car also just got brand new wheels and tires with the axle swap.
