http://www2.towerhobbies.com/cgi-bin...?FVSEARCH=a825
http://www2.towerhobbies.com/cgi-bin...?&I=LXM766&P=7 or
http://www2.towerhobbies.com/cgi-bin...&I=LXD109&P=ML (i think your better off with the bearings)
i think its a 5/16 tension pin, you can get this from home depot or a hardware store, you will have to cut it down to a 1/4 inch or so, if you get it, let me know and i will explain it to you.