We replaced our Transmasters with the MAXXIS LS E Rated tire and have had them for approx 2.5 years now. We go out several times and year and load out trailer with almost max weight and no problems.
Also check the tongue on your trailer and see how thick it is. WW had issue's with thin tongues that were 1/8" on the SL's and replaced them with 3/16" thick steel tongues. The 1/8" were actually bending up substantially over time.
Not sure about the SL's having sides that fail but when we took ours in after the first year for some small items to get fixed they actully did add some additional outrigger bracing to the outside of our frame an dto the trailer and one small piece of tube steel joining to cross members on the underside of our trailer. I noticed it when we picked it up from the maitenance work because the frame had new paint on it. WW just did it, I never asked them to. After 8 years and many trips out, no problems to date with the frame or sides failing.
Good luck and have fun with your new toy,,,,,,,, hauler. LOL.
