I've been trying to track down some resonant vibrations in the car that happen at ~62-68 MPH. It feels like the hatch vibrating away on something, maybe its the precision seal thats not letting the hatch sit? I dont see any wear marks. Only feel the resonance on the hatch panel.
I replaced the diff fluid, went from 75w-90 to some 80w-90 that i had in the shed. I pulled the driver side axle to inspect the u-joints, i removed the u-joints to inspect for any binding, reinstalled the u-joints. I then sat around and though about what else could be the problem and realized I had a new diff mount in my parts pile, so i replaced that as well.
The resonance has somewhat been reduced, but its still present...😞