Replace it.
A transmission mount, as its name implies, is a place for the transmission to mount to the vehicle. It is also used to dampen vibrations from the transmission.
Begin by loosening your 1991 Chevy Camaro transmission mount bolt. Jack the transmission up a few inches. Remove the transmission mount bolt and the transmission mount bushing. Put the new transmission mount bushing in and reverse the process.
Loosen the transmission mount retaining bolts. Loosen the back to engine retaining bolts. Jack the transmission of approximately 1 inch. Remove the transmission mount bolts. Remove the transmission mount. Reverse the process to install the new transmission mount.
a vibrating transmission could be caused by a bad transmission mount. If the mount breaks then the transmission will physically move causing it to vibrate.
It's a transmission mount.
No practical way to repair a broken motor mount. Replace it with a new one.
The 1997 Chrysler Sebring transmission is equipped with two transmission mounts. There will be a transmission mount at the back of the transmission, on each side.
Loosen the rear transmission mount retaining bolt. Jack the transmission up a couple of inches. Remove the retaining bolt and the transmission mount.
It supports and holds the transmission in the vehicle from the underside of the transmission.
Likely either a bad/failing motor mount, or a bad transmission mount. Is it a manual or automatic transmission? If it's automatic; the clutch that controls the reverse gear could be going bad. Have your mounts checked first. Simple, easy to replace, and the least expensive of the repair solutions vs. a bad transmission or clutch.
To change the transmission mount on a 1973 Super Beetle, first, safely lift and secure the vehicle. Remove the bolts securing the transmission to the mount, then support the transmission with a jack. Unbolt the old mount from the chassis and install the new mount in its place. Finally, reattach the transmission to the new mount and lower the vehicle, ensuring all bolts are tightened to the manufacturer's specifications.
A good book on transmission repair at home is transmission repair at home for dummies. Not saying your a dummy, but it's a very useful book for anyone.