My tires are wearing on the outside 1/2 inch. The rest of the tire looks good. From the outside tread the outer 1/2 inch. It is strange. My air pressure is supposed to be 110 but you cannot put that much pressure in at truck stops. So I ran them for about 1500 miles at 90psi until I got them aired to 100 psi. Is this my problem? Should I go with the full 110psi?

Perhaps a few pictures would help the members make a guess at your tire issues. Also please state what brand and size you have might help. Age, distance traveled etc....

My tires are wearing on the outside 1/2 inch. The rest of the tire looks good. From the outside tread the outer 1/2 inch. It is strange. My air pressure is supposed to be 110 but you cannot put that much pressure in at truck stops. So I ran them for about 1500 miles at 90psi until I got them aired to 100 psi. Is this my problem? Should I go with the full 110psi?

at 90 PSI the tires where overloaded if your running 16" tires , this will show excessive wear on the outside edge. The Goodyear tires show heavy wear on the outside regairdless if they have the correct pressure. Keep the tires at 110psi cold , check them fist thing in the morning before you get on the road. ITs also possible you need to have the alinement check. you may have a bent axel causing tires to wear uneven. I would suggest going to Morryde for IS 8000lb , the 7000lb axels are a time bomb on these trailer is your running with lots of camping gear. My trailer easily reach its 16500 gvw . When I pulled into Morryde I was 16300 and axle weight 13000lbs.

Quick check is look at the distance between the two trailer tires , should be about 4" on both sides if the trailer was pulled strait to unload the twist on the axels. if its close on one side you possible have a broken suspension part like a spring bolt or shackle link plate.

If all 4 are wearing about the same then probably ok. Rv tires wear differently than autos due to then scrubbing at every sharp turn. If you've ever watched your tires while backing 90 degrees into a sight you'd swear they'd roll off the rim. If the wear becomes severe or 1-2 tires start looking worse I'd have the alignment done.
As for the inflation, that's correct, inflate to max cold inflation stated on the tire sidewall, this gives you max load capacity on the tires.
As for the IS being a must, there's a lot of RWs out there without, mine was 1 of them with 7k axles with 60-70k miles on it & the only upgrades were the heavy shackles with wet bolts, disc brakes & 17.5" H rated tires. You bet I would've liked the IS, but budget didn't allow it.

Goodyear, two years old and about 30,000 miles on them

Goodyear, two years old and about 30,000 miles on them

Does the inside shoulder look the same? To me, I'm no tire authority, it looks much like my GY 614s did. My opinion would be since they have 30k on them to watch closely to make sure it doesn't get worse & go enjoy. When replacement time comes upgrade to the 17.5" H rated tires/wheels (Sailuns are a good choice).

Thanks

My G614's looked identical to that...

Goodyear told me it was normal and referred to it as "Shoulder Step" . . They even showed me a picture in their computer files stating what it was called...

I trust Goodyear, but still didn't like that answer so the next week I had a new set of G-114's and new 17.5 wheels

Goodyear, two years old and about 30,000 miles on them

Dave my Goodyear's look like this , not as deep but mine only have 15,000 miles. Some of mine had slightly different wear inside to outside edge and some worse then others. I think its normal for that tire, that's way most heavy truck trailer tires have solid shoulders in high scrub applications.

If these are still the OEM tires you have done well on tread wear but its would be time to change them out based on age. at 7 years on the ground its time to change them , they should be inspected for cracks in the treaded area and if any are found taken out of service regardless of age. Sailun is what I have on my 17.5" wheels.

This is my tire info
ST235/80R16