OC-3 sprocket problem

[mtncrawler]

On my '56 OC-3 it looks like the sprocket center was cut out (possibly because of wallowed out lug nut holes) and replaced with a piece which doesn't have tapered holes. The cone shaped washers will not fit in and as a result the drive sprocket lug nuts come loose. I have a Jensen manual that states in the forward that grade 9 bolts can be used instead of the factory studs/nuts which would solve my lack of taper problem. Anybody have any experience with doing this or do I need to get a machine shop to cut taper in the sproket holes? Don't suppose I could buy a sort of drill bit I could chuck up in a half inch drill that will cut this?

[Robert Barbour]

You would be better off getting the holes tapered and using the tapered washers with either the original studs and nuts or the G 9 bolts.  The taper washers hold up much better to the constant changing of direction which tends to losen bolts quickly.  If your machine is more for show than work you may get by with straight holes but check them often.  If you plan to do some work with it, then I would fix it right as another failure will be expensive.

[mtncrawler]

So a machine shop really needs to do the work? This isn't something I could do myself?

[Blake Malkamaki]

I think you could get or borrow a tapered reamer with a 1/2" stem that you could put in your drill. Should not take much to cut that stuff.

[Robert Barbour]

If I remember correctly the bolts are 9/16 or 5/8 diameter which would make the washers about an inch in diameter. I think for that you would need a heavy duty drill press with a counter sink of the right angle to match the taper washers. If you do not have the equipment, this is not a difficult job for a machine shop and should not cost much to get done.  You need to get the washers first so they know what taper you need.

[Ray]

if it costs too much to machine, I have new center plates allready made up to replace center in sprockets.
Ray

[amahle]

anyone know where I can get sprocket cones

[Jack in NB]

Quick and dirty fix: regrind a 1" drill so the point approximates the taper of the collets.

Retighten the nuts every few hours until they seat effectively.