Steering Shaft Help

[popsmick12]

I developed a clunk in the front end which turned out to be looseness in the steering shaft. It only happens when I hit sharp bumps. I can wiggle it by hand enough to recreate the noise. The shaft is enclosed in a plastic slip sleeve and I can't see how it is fabricated. I am assuming it has u-joints or something similar. has anyone had to repair or replace the steering shaft? If so what am I getting into to repair?