From Utah. 67 Barracuda Fastback. Hello!!

I do believe it is a sure grip. Both wheels spin the same direction when it is up on a jack and you spin the wheels. I see no evidence of any broken teeth on any of the gears. The pieces that were in the housing look like brass and they have the appearance of some type of shear pin. About a quarter inch in diameter. Looks like they got chewed up real good by the gears. The hole in the housing is directly behind the third member in the actual rear end carrier ( I think that's what it is called). these pieces were picked up by the ring gear and smashed into the back of the bubble shaped housing on the lower right side. split the housing in a semi circular pattern on the lower hole one and only a bulge in the housing where it caught on the upper one.