Time for new or HD springs. If the sled bounces up when compressed, its time for shocks. Make sure the springs are set at the higher tension on the adjusters.
Polaris has three differnet diameter sized springs for that suspension. Depending on the weight of the rider pick up a new set. I would not bother trying a used set as they are probably shot too. I had to do the same thing with 98 500 I had.
