Contact Heartland and Lippert/Dexter . . .
On our previous 2013 Heartland Trail Runner, the springs and axles went bad after the warranty, but with less than 5000 miles on the trailer.
(To be honest, I think that they were bad the day we bought the trailer . . . but that is another story).
We were on our way to Arizona when we discovered the trailer was bottoming out on the tires and ripping them to shreds.
Took a little work . . . but got Heartland/Lippert to replace the axles and springs (although I had to pay the labor charges and upgrade to larger wheels and tires, not too mention a $1000 wheel bearing burnout in Phoenix while on that trip, so cost us close to $3000 out of pocket).
My advice . . . empty the trailer completely and then take it somewhere to get it weighed . . . PRONTO!
Turned out that our Trail Runner empty weighed over 1000 pounds more than what the springs and axles from the factory were rated for.
Before and after replacement shots:
