there are 2 versions of the 47 blower, the old style has a gearcase on the back of the blower (the tractor side)
and the newer quick hitch style have a chain and sprocket drive sytem.
If you have the chain drive, it could be as simple as replacing/repairing the chain. if it's the
gearcase, you may want to unhook the snowblower driveshaft from the tractor, and turn it while
watching to see what turns as you go thru the gearcase on the back of the blower, and then
on into the gearcase in between the augers.