1000cc watercooled 8 valve

Heavy duty cases were not available at the time - you had no choice but to weld up the PTO. This worked OK if they were heat treated afterward. Photo below shows my reinforced case with outrigger bearing from the 1980s. My race 850 was splitting the cases and flexing the tranny shafts so much that the gears were wearing on an angle - so in went the outrigger.

I don't have any clarification on the 5th gear overdrive box idea. There was a 6 speed box available in the 80s that required a spacer for the case to accommodate the extra gears.

Jim,
That comment was meant tongue in cheek, as the cases appear to be the only Norton parts left. I do hope you can find out more regarding the 'box though.

jseng1 said:

There was a 6 speed box available in the 80s that required a spacer for the case to accommodate the extra gears.

Click to expand...

The original Shaftleitner 6-speed used a spacer. The Nova 6-speed, which is still available, and is based on the Shaftleitner, manages to fit into the AMC cases without a spacer. Neither one is strong enough to be used reliably in a Commando race bike. They were originally meant for the racing singles (Manx, etc.)/

Ken

I don't have any details on the 5 speed overdrive. Just this photo. Note the 3rd fork. The rest will have to be a mystery.

The TTI box is a development of the Schafleitner. Is it strong enough to use behind a commando race motor ? Bruce Verdon claims that it will cop 80 BHP easily.