Joe, I'll be honest, it could be as simple as a backlash adjustment that you can eliminate with shimming. BUT, it takes special tools for measuring and knowing what the heck your doing. Yes, any mechanic with the training, tools and spec's could do it, just finding one that would do it. Most just want to replace something, not repair it. And yes that is the name we call it. The British I believe call the ring gear a crown gear, can't remember what the call the pinion gear off hand.
Greetings, Earthling. We come in peace... Never mind "Paris to Dakar", the VehiCROSS looks ready for the Martian desert.