The problem: When riding uphill in sand dunes, 2-wheel drive, the rear end starts to bounce as it looses traction, and I do mean bounce. Not as bad in 4-wheel drive but still very noticeable. Everything is still stock when it comes to my suspension and tires. My question is what is causing this? Need to adjust my shocks? Need to replace the rear springs (firmer)? Crappy Tires? Looking to make upgrades this Winter to my 800 Trail and want to spend my $$ wisely. Thanks for the help.