Hi-CO Rotary Mower 60in, PTO and shaft spinning but blades not

[tdpalms]

I picked up a tractor recently that came with a Hi-Co rotary mower. The PTO and shaft spin at full speed, but the blades don't move at all. They will turn if I reach underneath and push them by hand. This is the first rotary mower I have owned so I know virtually nothing about them. Should I just buy an aftermarket gearbox and replace the whole thing? I have read a lot of posts saying to check the shear pin/bolt, but admittedly I don't what where or what to look for on that. Any help would be appreciated!

Thanks

 

[Roadworthy]

You may have a slip clutch in the line or your could have a shear bolt. Turn the drive shaft by hand to see if the input to the gearbox turns. If the input shaft on the gearbox turns and the blades don't your problem's at that end. If you turn the PTO shaft and the gearbox input shaft doesn't turn your problem is power not getting to the gearbox. Troubleshoot the problem before throwing money at it.

 

[dusty3030]

99% likely you sheared the shear bolt. That is what it's supposed to do it's a fuse to protect the cutter from breaking something. Just google rotary cutter shear bolt and you'll figure it out.
It will be a bolt that goes perpendicular through the coupling where the PTO shaft attaches to the rotary cutter gear box. Replace with same size bolt from the hardware store, get a regular cheap grade 2, not the super strong grade 8. Remember, you want it to break if you hit something, that is what it's supposed to do.