M-5's were sold with either shear bolt drive or slip clutch. They use a gearbox design particular to many Woods cutters that uses the blade bar to set the downshaft bearing preload. My personal opinion is this is just about the dumbest way to adjust tapered roller bearings I have ever seen. But to be fair, they did it for years on many models. If the gearbox has any kind of lubricant in it at all, and the blade bar isn't covered in the same stuff, it probably is OK at $350. But I would not own one.