Yeah, sector shafts fail, looks like a fatigue failure with a few (usually close to 400,000km) on them.
Rangier Rover had one go on his 120 and he went off the road and through a farm fence, scared the willies out of him.
A few of the South American boys have had them fail too.
Apparently the D2 'box is stronger according to Adwest, but it won't fit.

