most axles are suppose to have a bow in them. and tt manufactures do put low level stuff on tt's even tires I had a forest river that had 14 and 15 inch tires on it. found this out after I had several blow outs. Over the years and with as many tt's as I've had I never go with factory tires , first thing I do it go have the bears repacked and larger wheels and tires on, ended a lot of troubles down the road. some have asked why the bearings repacked. simple, I will this of you , if the quality of the workmanship on new tt's is so damned bad, what makes you think they packed the wheel bearing correctly