It's likely NOT the opto-- carefully check the shaft of the wheel (you may have to remove it). It's likely it's cracked and causing it to wobble- resulting in the error 41.
You really need to have a bright flashlight to inspect it if you don't remove it.
Be sure to mark the position you took it off at as it has a "home" position. If that's not right your awards won't line up with the wheel when you put it back.
Been there. Done that!..... good luck!