Soundguy said:
Sounds like time for a 20$ cobalt/TNT drill bit, some sweat equity and a 75$ pto shaft from tsc to me, and go with greg_g's advice.. Lil bit o' cutting oil and a jig to drill straight and a 1.25" shaft should go pretty quick.
Soundguy
Yup, its time to get a shaft from Agri-Supply or TSC etc, and drill the gearbox shaft for a 1/2" through-bolt. That way you can have a supply of cheap grade 2 hardware store bolts and always have the right shear pin in stock.
Usually its tough to make a through-hole line up at both ends (even with a drill jig), so here's a shade-tree way to drill the hole that has worked well for me.
First, push the new u-joint end onto the shaft. Then, using a 1/2" dia drill bit in the u-joint hole, drill into the shaft a little from each side - creating centers. Now use a smaller drill - say 5/16" and go halfway thru from each side, linking up in the middle. Be very careful when it breaks thru in the center - don't want to break off the drill in there. Carefully open the hole a little at a time - maybe use a 3/8" , then 7/16" and finally 1/2". The original holes may not line up exactly in the center, but each larger drill will tend to align the thru hole, so the 1/2" bolt will go in and fit well at the shear locations.
And if you want to get really fancy, you could locate the 1/2" hole so the shaft comes thru the u-joint a little and drill another small hole thru the shaft for a keeper wire (like a bent nail). That way when the shear bolt shears, the joint will just spin without sliding off and whipping around.
