Where to get steering alignment done for a class A?

I'm going to recommend the Manufacturer of the motorhome. We had ours "aligned" several times, even at Freightliner but...last time was the factory. They found the rear axle about one inch maybe two right side ahead of the left side on the frame. Had to remove some welds and weld in spacers/washers. After that and realignment no fighting the steering wheel.