Shaft-Driven Motorcycle Problems

There are time when I get so angry over the repairs I have to do as a mechanic that I can't see straight. Call this catastrophe 'All for the sake of a blob of grease.'

On the majority of shaft-driven motorcycles, there are splines in the rear wheel which mesh with splines in the final drive housing. All it takes to keep these splines alive is, at every rear tire change, a palmful of high-temperature grease. Forgo that lubrication for two or three tire changes, add in some wet weather riding, and those splines will rust and strip in short order.

The splines on the wheel side are available separately and usually affordable, but those in the gear case are part of the ring gear, which means a full tear-down with a new (costly) matched pinion/ring/gear set. Years back, I would go through this tiresome, gear-case rebuild song and dance, but given the many shop hours, special tools necessary, and huge shim selection required to properly align the ring, pinion, and gear, it became more expedient to simply order a new final drive assembly – and the money's about the same.

I recently did this soul-destroying job on a Yamaha V-Star 650, parts are still the most expensive part of the operation. The elderly gent who owns the motorcycle has every right to track down the idiot that installed the last rear tire and soundly kick his behind for skimping on the 5 to 10 Baht worth of grease...