Posted for "Mark Ravinski" <mjrav@comcast.net>:

 Randy,
 If I remember right, most of the wear was on the aluminum.  I should take
 another look.
 Wiring the bolt sounds like a good idea.
 
 A good way to drill the link is to chuck a 1/4" dowell in your drillpress
 first.
 Run the dowell into the hole (drill motor off) and eyeball position the link
 where you want to center the hole.  Then firmly clamp the link there for the
 drilling and reaming.
 
 Mark Ravinski


[McMaster Carr has 1/4" ID, 5/16" OD, x 1/2" oilite bearings for under a buck. Opening that hole to only 5/16 removes a minimum amount of material from the link and still allows for the bushing to be insered.  Drll to 19/64 or even to a letter "N" drill if you have it and then ream.  Ream at the lowest RPM possible and use plenty of lubricant.  Chamfer the edges of your reamed hole with a countersink to allow the bearing to self-center during insertion.  If you don't have an arbor press you can use your drill press quill to get the bearing inserted.  I hope these few notes help.   <Marv>   ]