Back when I had a Class C as well as now with a Class A, I've always had good luck getting service from truck shops that handle medium and heavy duty trucks. You may have to call a few, but there's a good chance someone will be happy to take your money. I used a truck shop in Tennessee some years back when our previous motorhome dumped the transmission. They sourced a Ford remanned one from a dealer in Pennsylvania and even though they didn't have any bays available, they did the tranny swap in one day in their parking lot. While waiting a few days for the new tranny to arrive, they towed our coach to a nearby campground so we could comfortably stay in it.
