Rack and pinion

Does anybody know why the rack & pinion (if I spelled it right) keeps going out on my 1996 SC Riviera. This is the third time. Each time is anywhere from 13 to 16 months apart. I am at a loss as to why this is happening. I am afraid to take it back to the Buick Dealership in my town.
Any information will be appreciated.
Thank-you,
Rose

What's going bad on the rack?