John *.?-!.* cub owner wrote:didn't the ones for the 52R combine have a second groove on the crankshaft pulley? I read someplace that it drove the unloader auger.
Not on the 52R, can't speak for the early 64's that replaced the 52R. The unloading auger, if it had one, was driven off the rear of the combine's main gearbox.