Is yours the HF with the bolt-on gearbox or is it cast into the sawframe?
The Files section has a manual for a HF37151 with bolt-on gearbox, which has a shaft with a circlip on it.
The parts list is crudely drawn but seems to show the oil seal on the outside , then 2 bearings then the circlip.? Then there's a 'pin' which you don't show (but might be a key) since the next part is the brass gear.?
The following site shows dismantling and rebuilding of a bolt on HF gearbox:?.? Doesn't go into the output side of the gearbox, but you might appeal to the site owner for any extra info he might have.
Rgds - jv
