On Snapper the disc on crankshaft walk up and move away from wheel if wheel still has rubber its still good. There 2 set screws in disc loose both move disc down that way fix slipping wheel. tighten 2 set screws. It don't take much to move disc down while in neutral wheel in center disc not touching disc don't pull down to for to touches. Rubber on wheel worn down about 3/8 inch disc move down that much make go again with out slipping. You press clutch down after adjusting disc put in about third speed let off clutch front wheels jump off ground. All along warn rubber on wheel.

It's not the disc on the crankshaft, it's the HUB that the driven disc( the one with the rubber is on) is mounted on