Ok so it’s not the wheels or tires. And I had wheel spacers on the rear 1/2 inch and I took them off and drove it. The vibration is much better but it’s still there. When I shift it in to neutral while it’s vibrating it goes away. What does that mean?
The pinion angle looks to be really good actually. Goes slightly downwards. The transmission mounts are tight also I just checked them. I jacked up the rear and my passenger tire spins round perfect the driver side ever so slightly doesn’t spin perfectly round but I don’t think it’s enough to cause that vibration and even if it was it still should vibrate when I’m driving down the road and put it in neutral, but it doesn’t. The vibration goes away when I put it in neutral going like 40. Really sounds like an unbalanced driveshaft right? I looked at the driveshaft and there are weights on it I’m not sure how it would loose it’s balance
Then might just pass on what I just posted for now & look at it might be a bad bearing, axle has excessive wear at the bearing contact. But again theory. Might be best to spend the day starting from the simple you haven't checked out yet the work you way up to ensure things are ruled out.
Could be the sound damping material inside the shaft decomposing and moving around....maybe
