27-11-2024, 09:12 AM
Hi
These are self-aligning bearings, and the bearing rings with the part-spherical outer faces are supposed to be a reasonably tight fit in the two halves of the chassis bracket but not so tight as to bind. I suspect this was partly to accommodate assembly tolerance and partly to allow for chassis flex. They certainly shouldn't rattle or rotate, rotation only happens when the inner bearings seize up. You could try some shimming/packing between the spherical parts and the chassis brackets, but this needs to be robust enough to stay in place reliably. A custom turned brass ring might be the best bet. The two halves of the chassis bracket are riveted together, these may be drilled out and replaced with cap head screws and nylocs if you need to disassemble.
The shaft rotation takes place between the inner steel shaft and the "top hat" zinc liners. I think Austin chose zinc as it is to some extent self lubricating and could withstand lack of oiling. Maybe not 90 years of no oil though.... You can buy new brass versions of the top hats, but I seem to remember they may need slitting and filing to reduce them to the exact diameter needed. I would describe the ideal shaft to liner clearance as an easy fit, i.e. looser than a nice tight fit but not a fair amount of slop.
These are self-aligning bearings, and the bearing rings with the part-spherical outer faces are supposed to be a reasonably tight fit in the two halves of the chassis bracket but not so tight as to bind. I suspect this was partly to accommodate assembly tolerance and partly to allow for chassis flex. They certainly shouldn't rattle or rotate, rotation only happens when the inner bearings seize up. You could try some shimming/packing between the spherical parts and the chassis brackets, but this needs to be robust enough to stay in place reliably. A custom turned brass ring might be the best bet. The two halves of the chassis bracket are riveted together, these may be drilled out and replaced with cap head screws and nylocs if you need to disassemble.
The shaft rotation takes place between the inner steel shaft and the "top hat" zinc liners. I think Austin chose zinc as it is to some extent self lubricating and could withstand lack of oiling. Maybe not 90 years of no oil though.... You can buy new brass versions of the top hats, but I seem to remember they may need slitting and filing to reduce them to the exact diameter needed. I would describe the ideal shaft to liner clearance as an easy fit, i.e. looser than a nice tight fit but not a fair amount of slop.