I have found that when lightning does damage like that, it has probably fried several more components that are not showing it.
You may be wasting your time on replacing the two components. (But you may not be, who knows?)
I dont know what a Mighty Mule 500 Gate Opener is, but if it is opening a metal gate as the name suggests, you may want to sink a couple more ground rods and attach them directly to the metal gate.
Lightning is seeking a path to ground, sometimes the surge is so great that the conventional ground rod is not enough, so it finds other paths to help make up.
(Some engineers think the current flow is from ground to sky, but lets dont get into physics here.)
You may need to call the power company and ask them to do a ground check on your property, or at least recommend someone who can do it. (It's a special instrument to measure ground (dirt) resistance. most normal electricians wont have it.)
Plus it would never hurt to bury another ground rod at the power entrance to the house or whatever feeds the gate opener. Hammer it into the ground about a foot or so away from the current existing one, then just connect them together with a #6 AWG copper wire.
If you decide to do this:
Do not disconnect the wire that is currently on the ground rod. If the transformer on the pole is bad and leaking current to ground, and if you get into the path between the ground wire and the ground rod, well it can be hazardous.
If you dont feel good about this, call a licensed electrician.