Fixing a loose side mirror?
 

My truck has the extra wide trailer-towing type mirrors and thanks to all those dangerous pedestrians walking along the sidewalk, my passenger side one has been knocked out of adjustment alot.

Its gotten to the point where it won't hold an adjustment anymore. The mirror itself sits on a shaft with a rubber gasket to give it some grip. In theory you can adjust it where you want and then shove it tight on the shaft to hold position but it goes out again with the first gust of wind.

This wasn't a big deal until I started hauling my ATV in back. Now I'm half blind because I can't see out the back and the mirror keeps pointing at the ground. Do I need another mirror out of the junkyard or is there a way to fix this?