A mechanical coin mechanism (coin chute to us old farts) MUST BE KEPT CLEANED, POLISHED, AND LEVEL in order to work properly. You must also use the correct coins that the particular unit is designed for.
The cradle must pivot easily. It's only held on the shaft with a very tiny e-ring so you'd need a jeweler's screwdriver to pop it off. Don't lose that little e-ring since it's metric and you would never find that size at a hardware store.