Lube will help, something like waterproof grease so rain doesn't wash it away.
WD-40 is useless as a lube. WD stands for water displacement
and got its start after a hurricane
. It's made to dry out breakers/electrical equipment
and evaporates quickly leaving very little oil
Suppliers that cater to machine shops have many bushings of different metals and sizes. Probably available on line. It's not that difficult to drill out the aluminum
and insert a bushing of a more durable metal. If you do it right, you freeze the bushing and when it's installed it expands and makes a tight fit.
Or find an aluminum shackle and hook to it. Each will wear, but takes twice as long.