i assume you are talking about the PTO shaft. that connects between the PTO on back of your tractor, and runs down to the gear box on the finishing mower?
if that is the case, any local farm store should have a new PTO shaft shield. tractor supply, farmking, farmandfleet.
the issue with some PTO shaft shields, is they make different types of PTO shafts, rated for different things as a result different shapes and size of PTO shafts are out there. and in that different shields to fit. most of the time new PTO shafts come with new shields already on them. not always though more so when repairing portions of the PTO shaft.
if above is case, make sure you cut your new PTO shaft to correct length. both shaft and shield. "this is a normal thing that should be done"
www.everythingattachment.com has a video of measureing and cutting shielf and shaft peices down to correct length.
google something like "cut PTO shaft" and there are variety of typed out instructions.
having to short of shaft pieces = shaft coming apart, possible, if you say go down into a ditch and then come back up, causing the finish mower to drop down real far.
having to long of a shaft pieces = when ya raise finshing mower up. and the 3pt hitch still has room to go up, but is being hung up due to the pto shaft pieces will not go up. (shaft bends / buckles and your in trouble)
again its normal to buy a slightly longer shaft, and then cut it down correctly. (every tractor and implement) will measure slightly different for min/max length. the PTO shaft will need to be.
