Why the LCA bushing has the hexagon instead of round hole?

[George Hill]

Again, to clear up the misinformation, that is a non-M bushing, M3s are solid.

[sapote]

Again, to clear up the misinformation, that is a non-M bushing, M3s are solid.

Yes, it's the bushing from my 325iT and had stated that when posting the pics.

[digger]

This broken bushing inner sleeve shows the metal ring R outer layer after the hex rubber which is about 2mm thick. So if the rounded shaft worn down the hex rubber part, metal ring R will act as a bearing for the shaft to rotate, preventing the rubber bushing B from ruptured as on the stock part.Worst case this will have 2mm plays instead of more than 20mm plays with the completely ruptured donut B.

here is an idea, maybe periodically change the part that is designed to be a maintenance item (with a good brand item and install it correctly) and it wont rupture nor will it have 2mm of play. This approach has worked well for the last 40 years