I have tightened up a lot of my 300D steering with upper control arms, tie rods, idler arm repair, etc. I did a complete front end rebuild as well as a rear rebuild

The only remaining problems is a manageable wander at highway speeds, about +/- 1.5" of play and the fact that I have to hold the wheel at 15 degrees to the right to go in a straight line .

I noticed that the steering coupling has a hairline crack all the way through from one edge to the center on one side and another crack just starting on the adjacent side of the coupling. The rubber is very hard, but not dissolving, and appears intact.

Does anyone think that I will gain $60 (partshop price with shipping) worth of benefit from replacing it?

Overall, it seems like my steering is pretty good, though not the same as the first day it was driven. I am not super enthusiastic about adjusting the steering box at this point.