They are shot, they die of old age. If you want to check, look for ANY
space between bar and bushing. They fit, when new, by compression and
there should be NO clearance at all.
Also check the brackets for the body mounts -- they tend to fracture
and rattle. Cheap and easy to replace, but you may have to take the
sway bar off to see.
This is a very easy job -- on level ground, all you have to do is drop
the body pan, unscrew the eight nuts, replace bushings, and re-install,
no need to jack it up, just turn the front wheels for access at the
control arm. If the ground isn't level, however, getting the body
mounts back on is a pain.
Peter