There is a reason they have trailer tires and truck tires.  Trailer tires are designed to deal with the stresses that a trailer puts out.  If your trailer tires are wearing out fast then maybe there is something wrong or your just flat out towing a lot.  All the trailers we have at our shop last forever besides being ripped apart by bad drivers. 

Just imagine your truck with an extra truck on top of it.  The weight distribution on a trailer isnt the same as on truck. The weight moves around a lot more which puts tons of stress on the sidewalls of the tire.  This is a main reason for blow outs on trailers. Trailer tires arent designed for speed like normal radial is. If you really want to save a few bucks then get radials or cheap trailer tires but in the long run you will end up paying for it one way or another.  I have seen plenty do it with fairly good luck but to me its just luck.  I was a over the road truck driver and I cant tell ya how many times I got pissed of due to low quality tires blowing apart when they were new.

trailer tires are designed to be abused... scrubbing (while turning), different heat cycles, weathering, and most importantly, trailers dont have the same suspension as your average truck, the trailer tires just plain get beat.....

that being said.... i have LT tires on my hauler lol... and alum wheels.... which is also considered a no no lol..then again i only tow my 4runner maybe 60 miles one way... and never over 65... so?

You might get away with a LOAD RANGE E truck tire...........

An auto tire isn't strong enough.

not sure on the axle alignment.  i didn't build the trailer, its a Big Tex 19' car hualer.  Max tire pressure is 55 lbs and I run them at 50 all the time.  the front tires do wear faster.  If I was in bakersfield right now I would be near an America's tire, but i'm not.  Probably going to go to Big Brand or Tire Pro's.  Think I might give the Radial's a shot, or just see what the shop recomends.

if i had the cash id be buying trailer tires to replace the  truck tires on my trailer.. had one blow out sunday just sitting in my yard and the trailer hadnt been on the road in over a month.

Pretty much what was said before.. LT tires just arent built to deal with the stress a trailer puts on them

Lose like a LOT of side slop or takes a little force to wiggle em.  Trailer shackles are normally snug but if they are too tight you will wear out the spring bushing.  Which is what I am guess is the case with yours. I will say if they have been loose for a while now it very well could account for the excessive tire wear since it would allow one axle to off track. I would take the shackle off and check the bushings before tightening them back up. If bushing are fine then just make sure you allow the shackle to move freely. The main reason I mention this is because trailer axles have leaf spring which are connected in the middle.  So the shackles will move a lot more then a shackle on our rigs. Dont forget to slap some grease in them while you have it apart. Mind as well check all the wheel bearing too ! LoL nice little list for ya.

Radial trailer tires are awesome. Every trailer I have (between my father and I thats about 15) has radials. They tow better and last longer.