if you can fish out the broken half in the case just buy a new 1 inch x 1/4 dowel pin as a replacement ,, if you can't get the broken part out of the case reverse the cross pin and carefully drill a 1/4 inch hole in the opposite side of the case making sure the hole is centered in the opening and deep enough so the pin sits flush with the top of the cross pin when installed. make sure your spider gears did not weld themselves to the cross pin , if they have and you cannot free them up it is time to buy a new sure grip as there are NO spider and side gears available any where for that unit.