Hello, just picked up an unmolested one owner Polaris trail boss 350 4x4, less then a 1,000 miles. Well when I got it, whenever the 4wd system engaged it would make very loud clicks about half a seccod apart. Then as time went on the clicks bacame more rapid until today when the whole system in inoperative. What do you think? If its in 2wd in goes like crazy.

 

Sounds like a mechanical problem in the hubs or could even be a drive shaft problem.You can check the hub fluid,but may be dry,plus damage may already happened if hubs are making noise and it's not a drive shaft problem. Several videos on youtube on this,but nothing beats a manual,especially if this machine is new to you.It's an electro/mechanical system and has to have 12 volts to the hubs also.Here's a cheap pdf one for 5 bucks.DOWNLOAD 1985-1995 Polaris ATV Repair Manual ALL MODELS - Download ...
Plus here's the video on parts involved in the hubs.On a 500,but has the same system.

 

okay, so today i took a look at everything. it turns out that the chain sprocket on the front axle is worn smooth... how do i go about changing it?

 

Center eccentric housing has to be loosened along with the front housing to slip the chain off of the sprocket. The a-arm needs to be dropped from the strut,clevis pin needs to be removed from the front of the drive shaft so it can be pulled away from the sprocket.Then you can get to the sprocket to change it out along with the chain if needed. Again the manual makes this easier to under stand.