Tire wear

We took delivery of our new BH 3400RL last December. I ordered the trailer with the axles upgraded to the 7000# w/G rated tires. I have them inflated to 108#. I check the air every time we move the trailer. We just returned from our first trip, round trip to Arizona ( a little over 2000 mi. ). We I got home we took her in for some minor warranty work. I also noticed what I think is excessive tire wear on the outside side walls of all 4 tires. When I pointed it out to the dealer he suggested I run with less air. This seems backwards for side wall wear. I ask that they check the axles and also make sure it is trailing properly, but have a sneaky suspension this won't happen. Has anyone out there had similar tire wear? And will I need to contact Heartland myself to pursue this issue?

When we took delivery of our 08 3400RL the rear axle was severely bent on the left rear. Didn't notice it on the pre-delivery but it absolutely shredded that tire in only a few hundred miles. Put the spare on to get it back to the dealer and it shredded that one too- in only a hundred miles. Dealer changed out both axles (and 3 tires) on Lipperts dime and no problems since. Ours are only 6000# and E rated. I think the dealer should step up to the plate.