I have a noise in the right rear corner of my 90 W126. Only happens very occasionally when going over a quick bump. Sounds like a spring snapping back into place. That is about the only way I could describe it. The car has 64K miles 300 model. Could this be suspension bushings? How long do they last?

good morning mr. holmes.
i have a similar problem in the 560sl. sometimes the car when settling or stressed will let out a sound as if it, for lack of a better term, is passing gas...could this be bushings? or what else?
thanks