I have of 566-54 Plastic Coupler Knuckle where the plastic spring broke. These are certainly easier to install than the cast ones, but apparently don't last as long.
I tried replacing the plastic coupler with a traditional one, but the spring wouldn't open the coupler. Does anyone have any tips or tricks for replacing the plastic knuckle with something more reliable or do I just live with the fact they will need to be replaced more frequently.
Any help would be greatly appreciated!