I have been racing a Honda Crx-Si in ITA and FP for a number of years. The differential has an adapter sleeves that sizes the differential output to the bearings.
The problem I have experienced is that the adapter sleeves backed out onto the half shaft seal surfaces. They move out far enough to allow the differential to lose the support of the bearings. It and the ring gear then are free to rock. The result is that it destroys the shaft seals. I have been lucky in that no damage has been caused to the gears.
Can you give me some advice on what to do to stop this from happening in the future?