Corse I CV joints

[hollytree]

Right
Rear clam off. Both driveshafts off. Both calipers off. Exhaust off.
Left wheel bearing definitely gone. Rumbles and no spin. Right is quiet and quick flick it will turn nearly 360 deg on its own.
When taking right caliper off, this fell out from somwhere?
It is about 12mm x 6mm x 2mm , is rubber backed, stamped 5 on front and seems to show "contact" wear. Any ideas?

I think I will try to keep engine in, change wheel bearings and the right side CVs. (lefts done last week)
I will see if I can do diff to LSD in situ, and ask Craig about fitting cable shift.

Steve