Hi, looking for some help here…

I have had my 1970 LHD with overdrive since 1983. Have restored it more than once (different areas) in 40 years with me, but do not use it that often Recently took down clutch, flywheel and rear suspension because of some vibrations which I found in an unbalanced flywheel. After 3,500 rpm I started to feel a vibration everywhere, that is gone, the car feels terrific, problem now is when I reduce from 4th to 3rd or 3rd to 2nd, and when car is at operating temps, rear axle vibrates a lot and transmits it all the way into the front, I see the hood vibrating. It is like if wheels were getting “small non-constant blockages” Same thing happens if I rev in first gear and just let the engine do the braking, the wheels vibrate a lot. When I put reverse gear on sometimes rear axle like “jumps” because of getting these blockages. I have replaced all final drive supports, u joints, etc, but still have it. When car is cold it does not do it.
Any help will be appreciated.

 

This sound like a differential, driveshaft or rear axle UJ problem.

 

Thank you Greg, will check into that, also got recommended to check on the center bearing.