tachometer

["Lawrence A. Swift" <"mgtd51@shell1.shore.net"@shore.net>]

the tach on my 51td has stopped working.  i believe the gearbox is ok and 
that the way the gearbox mates to the generator is broken; i unscrewed 
the fitting and discovered several small chunks of metal.  can anyone 
tell me how the two mate?  is there a key on one of the shafts?  is there 
some sort of bushing that might have broken?

thanks

Larry Swift