Transmission mount

[JOE BYRNE]

I have noticed a vibration at 50 to 55 mph. Also when in 2nd and third if Im accelerating and let off and then hit it again I can feel a thump. Motor mounts are holding and shafts seem tight. Jacked up the tail of the transmission and looks like the rubber is beginning to seperate on the passenger side. How long should this job and any tips would be helpfull.

Thanks,