I've never used this place
myself but I have in my notes that Nassau Auto Spring is a good place to go especially for suspension problems which is their specialty (evidently, several RVers have used them for air bag/suspension issues).
They supposedly do alignments on all heavier vehicles but viewing their place on Google Street View (click here
), it appears as if their bays are limited in size. I'd give them a call and describe your rig and see what they say.
Nassau Auto Spring Truck Repair Springs Long Island NY
2110 Jericho Turnpike, Garden City, NY 11040 • 516-747-0645 •