need info on part of 1978 Chevy van g-10

I have a 1978 Chevy Van, G-10- 305 automatic. I have a steering problem. It steers ok, but upon looking under the hood I noticed the steering shaft [ or whatever it is ] doesn't look right. I need to know what part it is so I can fix it. I can't find out in the manual or online. I can send you a picture. Thank you. :banghead:

I found out that it is the steering coupler. I need to know how to replace it now on my 1978 chevy g-10 van. Automatic. Thanx, Michelle:banghead: