Hi guys !
I thought that I would pass along a repair that I did on my pull behind Mott flail mower. Hopefully it will get someone else mowing.
The shaft that runs from the top pulley to the right angle drive, is splined and goes into a splined sleeve on the gearbox. On my mower, the splines in the sleeve wore away, allowing the shaft to spin, and not drive the mower.
This wear may be common, as I have another gearbox from Grampa's that has the same problem.
I disassembled the end housing of the gearbox, (the end with the splined sleeve), chucked the sleeve in the lathe , and bored out the remaining splines, to a 1" I.D.
I cut a piece of 1" O.D. cold roll shaft to length, and cut a keyway in the end for the pulley. (5/16")
Placing the shaft into the splined sleeve (now bored to 1") I drilled a 5/16" hole thru the side of the sleeve, and thru the shaft. This becomes a location to put a bolt which will drive the shaft, and potentially be a shear pin if something tries to lock up the assembly.
Putting the sleeve back in the housing, I measured the location of the hole, and cut two slots , in the side of the housing, 180 degrees apart, the slot is wide enough to allow me to get sockets in to tighten the shear bolt.
I have an advantage of having a lathe and milling machine in my shop, but most people probably either have a friend with machine shop equipment or access to a small local machine shop.
I hope this helps someone.
On the mow again !