I guess so, but would like to hear other opinions: this car transmission (Fiat 126p) comes with the gearbox and differential in the same unit. When driving it, and more precisely when turning a corner it lost transmission completely, with a horrendous clanking noise in the differential area. With the car jacked and 1st speed engaged, if I turned a wheel I could replicate the clanking nasty noise while the other wheel wouldn't move.
With the unit off the car and disassembled, I found one of the differential bearings attached to the ring gear, which supports the differential unit on it the gearbox body, was virtually disintegrated: all the rollers were piled up in a corner while the cage was just two rings. If I try to "squeeze" both axles attached to the differential unit, I can't replicate the clanking noise, so I think the differential inner parts are ok. At a quick sight, I don't see gear damages.
So my question is: can a virtually nonexistent differential bearing affect the pinion/ring gear coupling SO dramatically, it could make the pinion jump and clank over the ring gear, making the differential "dead"?