I know our Marine dept. has bearing kits. To assume they fit Trailstar trailers is a stretch but you can call and ask. I just have them winterize my boat every year. For the $125 or so it cost it's worth it for me. They put the puter on the engine to put it to sleep, do the bearings, gas and make it ready for the next year while I'm out with the dogs bird hunting.
if your doing the work yourself - take a bearing and a race and the seal to napa they can cross it to there part numbers and your set - i did it every other year - never had a problem - i just changed them to be safe -