Vincent Black Shadow Gearbox

I wrestled with this for over a year before finally sitting down to figure it out.

The Vincent cases are new manufacture (made by Andy Molnar) and the gearbox is a Quaife/John Surtees 5 speed unit, also new manufacture.

Initially when assembled, the gears crashed and rattled as it shifted through the gears. I could shim it up to decrease dog interference, and everything worked OK until the whole unit was closed up tight. Once tightened, the entire transmission bound up solid and refused to move.

Using known good parts borrowed from generous vincent enthusiasts, i traced the problem to the post-machined bearing pockets on the remanufactured cases. just a millimeter or two too shallow, it seems. it was too late to get in there with the mill, so i opted to take the material out from the cover side. The transmission now requires custom shimming, but appears to shift freely through all 5 gears without noise.