Having installed both rear drive shafts, I can understand why they can (almost) independently rotate. This is the main purpose of the differential and allows one wheel to move at a different speed to the other so you can go around corners. What I didn't expect was that turning the prop shaft did not turn the drive shafts. It rotated freely and seemingly had no effect on the drive shafts. I was expecting some sort of direct linkage.
Is this normal, or do I have a problem with the diff?
I posted this query to the Rhocar forum and in return received this very interesting thread.
Rhocar link. There is a great U-tube link to a video showing how a Diff works - fascinating.
It turned out to be a school boy error in the end. The near side draft shaft was not fully located in the diff.