Hi all, I recently pulled my differential from my '20 490 since I had some sideways movement (~1/16" each direction) when I pushed and pulled on the wheels when it was up on stands. I suspected the thrust washer was shot - and was right when I got it apart - see picture (3 pieces). The new bronze one from a Model T supplier fits perfectly. I added additional .030" shims (also from Model T supplier) to close up the remaining gap in lateral movement. Also, while the car is a '20, I cannot definitively say the rear axle is the original. The ring and pinion are bevel cut in mine. As I understand, the bevel cut wasn't introduced until '22 in original assemblies, but there were replacements of the straight cut with bevel cut available as service items. Anyway, the question I have is the stamped numbers found on the mounting surface on the axle housings where the torque tube mounts. In this case, its stamped with a 576 on both halves of the axle housings. You'd never see these unless you pull the torque tube off. Does anyone know what these numbers mean?
The numbers on both side of the rear axle housing would be to ensure both halves that were machined together are assembled together and not mixed up during the further assembly processes.
