Hutch,
This is way out, but since no-one else has replied....
Firstly, I don't know the FB50 back axle set up, but some years ago I bought a 26 which was mostly in pieces. I suppose the general arrangement of the '19 and the '26 rear axles would have been similar though. When the pinion shaft was turned by hand it felt "strange". I replaced the pinion bearings and the diff carrier races, with no improvement, and could not get the ring and pinion gears to mark evenly using engineers blue no matter what I did. Eventually took it to a very experienced transmission mechanic who finally worked out that the ring gear and the pinion had come from two different differentials which had different ratios and were not a matched pair. We tried several other spare pinions which I had, and one of those mated very well indeed with the original ring gear. Although the ring gear and pinion that came with the car were set up in place, they obviously had come from two different vehicles, and would not have lasted any time at all if they had been run together.
Might be worth checking if you have the same problem, though it is surely unlikely.
Frank.
Last edited by franco; 12/01/09 12:45 AM.
