OC-3...Sprocket drive stud broken

[ted]

My machine has either 5 or 6 studs on the rear sprocket.  Anyhow, one has snapped off, about one half thread deep into the hole.  I drilled through it, tried an easy out, no luck.  Any suggestions???

[RAB]

Just looked in my OC-3 parts books, December '55 & Final Edition December, 1958. Show part # 117 540, (changed in later book to 607 790 F), stud - rear wheel drive, as 20 required - 10 each side.  You are in trouble if you only have four holding it on!
I would think it prudent to remove the drive sprocket and repair to working standard.
RAB

[ted]

Thanks, mine is earlier, only 6 (I can't go look right now) each side.  I'm looking for anyone that has experience in replacing a broken stud.  It does not seemed to be bottomed out in the stud hole. (I drilled a hole all the way through it)  Was early procedure to use lock tight?  I tried an easy out, but I was afraid it was going to snap.  I would like to do the rerpair with out removing the track and pulling the sproket.

[Mark C.]

If you have a torch, or can borrow one, I would put heat to the casting around the broken stud, heat it to a dull cherry coloured glow, and spray with penetrating oil while still hot then let cool. After cooling the stud may spin out with your easy-out. If not I reheat, and, try the easy-out while hot.

Failing this you can carefully blast most of the stud out with the torch and then remove the slag and run a thead cleaner(or tap) CAREFULLY AND GENTLY through, backing it out often.

Hope that is helpful.
Goodluck
Mark

[walter hudson]

try drilling the hole through the stud as large as possible without damaging the threads,then if you have a torch , heat inside the hole that you drilled and then use a small punch or chisel to punch what is left in toward the center of the hole, the larger you drill the easier this will be .
                                               good luck , walter

[yellowcrawler]

If the hub is not removed and much heat is applied, the seals will be ruined and the bearings could be affected.  If I remember correctly, the back side of the hub is open into the gear reduction, so any foreign material will end up inside of the gear reduction casing.  Most likely what has happened is that the stud was tightened up very hard up to the shoulder, making its removal difficult.  

I had to remove several broken studs from my hubs, but already had the hubs off.  Seals were shot and some bearings were bad, so I took care of all of the problems while I had it apart.

I have a later HG, but pictures of the early ones show 5 studs.

It may be best to pull the hub to make the repairs.

[Blake Malkamaki]

If the break is not too deep, take a nut of the same size or slightly smaller, hold it up to the broken stud and weld the center of the nut to the broken stud. Let it cool and try to turn the stud out. This may take several tries, but usually works.

Instead of using penetrating oil when heating the stud/casting up, use bees wax. It will melt and pull into the threads, but will not burn off as quickly as penetrating oil or motor oil.

Blake