Hello - I have the same exact sled, problem, and the Y.E.S. warranty until 4/17. I bought my sled used and a month ago ( 3,850 miles) and within two hours of riding had the mono-shock fail (so I thought). I brought it to NewportPowersports in Newport Maine and had them check it out. Also, asked to have the seat repaired/replaced under warranty.
They told me after a couple of days that the Y.E.S. warranty wouldn't cover the seat seam failure(although an obvious workmanship problem) and that the adjustment cable for the shock was broken and they wouldn't cover that either.
Good luck with your efforts! Please let me know if you have better results.
I plan to take mine to an auto upholstery guy for repair.
Regards,
Al