Guidelines from Dana with wide base tires

If you're thinking of using 'super singles' or wide base tires on your drive axles please note that some axle manufacturers will reduce the rating pf their nominally rated 40,000 lb. products based upon track. Wheel offset will impact the track. Keep in mind that no ratings are below 34,000 for the tandem set, so they still meet the Federal Bridge limit for the axle group. However, the stress on the bearings will be increased, perhaps resulting in increased maintenance.

http://media.spicerparts.com/cfs/files/media/4pqgszKWH344xmEzk/abib-0511r2.pdf?store=original