I'm hoping someone can tell me how the rear scarifier mounts on a 610. One came as part of the package with my old 610 and I went to mount it today with no luck. i thought i would use the hydraulics to latch it onto the rear frame hooks, but it's just slightly wider than the rear hooks and I'm guessing that i need some large pins or shoulder bolts as there are holes in the frame hooks/loops. Or maybe the scarifier frame is bent, but i don't think that's it.. any thoughts?? Thanks!