so i replaced my diff when I took it out I noticed inside the driveshaft...where the diff and driveshaft connect the rubber inside was damaged...and lets just say I wasn’t gentle...so after that it started vibrating at 15 mph and really never ends. So I replaced the diff. I went with a sc430 diff For better gas mileage due to the gear ratio. I bought a used driveshaft. It was in good condition no rust and all parts of driveshaft work good. But still vibrates. It does it on jack stands as well but instead of a deadly feeling vibration it makes super loud droneing sound. I never mess with i driveshaft till now I pretty much threw it in there did I miss a step when putting in driveshaft? I been stuck here months and need to get fixed.