Talked t a Polaris dealer and they were aware of the rattle.They said that all Polaris ATV's do it but that you don"t hear on the gas AtV's because of the engine noise. The rattling sound is as a result of the drive shafts splines rattling when no tension on two wheel drive,once the four wheel drive is engaged the front wheels are pulling and there is no longer play on the splines. The cure appears to be to use some anti seize compound on the splines so that they won't rattle. His explanation appears to make sense but I just wonder why Polaris has not come out with a technical bulletin and why they dont use the anti seize compound al the new units. Ant thought on this simple cure?