[Motor31]

Traveler there is another consideration to the tire wear issue. If you have had a tire changed and the jack was placed anywhere but under the spring pad then you probably have a bent axle. The axles that are installed under these units are thin walled steel tubes, just like the frames. They are not heavy enough to jack up anywhere on the tube except for the spring pad and the jack head has to be there and not on the tube itself.

I know from experience that the tire places just shove a heavy duty jack under the axle and crank it up because the folks are used to solid axles and do not know about the hollow tube style we have.

Something else is that the axle is installed with an arch to it. It should have a slight but noticeable arch upwards in the center section. If it is flat, it is bent due to overloading. If you have the older 7,000 lb axles, going to the 17.5 tires will not keep the axle from bending or going out of alignment. The new tires will wear out very quickly and unevenly. The 17.5 tires are also more expensive than the 16's so you will be losing even more money.