My sources for parts for my Troy Bilt model 47282 have all but dried up. Sears parts on line still has a few, plus some great parts diagrams. But.... when I took the rotor assembly off to replace the chipper blade the bushing that goes between the keyed shaft and the rotor assembly and fits into the shaft shield was unwound and destroyed. The parts diagram does not list this part, and sears "Expert" on line help contacted MTD and they never heard of a part that went in this location. It is made up of either heavy nylon or light gauge steel wrapping on a metal base 2 3/8" in diameter 5/8" thick. Has anyone come across this while working on their machines?
On the new chipper vacs the rotor assembly is now called the Impeller Assembly-shredder, but this part is not listed on the parts diagram either.

 

Can't you make a "Bushing" of a large Nut that will slide onto the shaft, or a whole bunch of Fender washers?
Post some photo's. Give us 'hackers' a chance to help out.