I experienced the same problem with my tractor. Had to split it so that I could access the throw-out bearing in the clutch area. In my case there were two roll-pins that attached the fork to the shaft. One of these roll-pins was smaller than the other and was inside the second roll-pin. I ended up removing the remains of these roll-pins and drilling the hole out to 1/4 inch diameter. Then I placed a 1/4 stainless steel bolt and lock nut in place of the pins. This has worked fine for several years since. The difficult part was getting it back together again. Hope this helps and good luck.