I have a 96 Polaris 425 4WD and I was hearing some grinding in the left front wheel. I put it up on a stand and I find that in 4WD all the wheels turn except the front left tire. Can you tell me what is going on and what I need to replace?

 

Could be as simple as the awd coil wire or wires disconnected on that side. Follow the gray and brown wires up to the connectors under the front panel.Also with a test light or meter see if the gray wire has voltage on that side when in gear and ignition switch on. If it does have power the problem could be mechanical. Drain the hub(Hopefully it has fluid) and inspect the armature plate,hilliard and the face of the coil sleeve for any damage.If it's been running dry because of strut or hub seal leakage damage can happen to these parts. Here's a video on the awd system. The manuals go into good detail also.The main wear points on the strut are the coil sleeve face and the inner pole of the strut. If they're damaged,repairs are needed or if ground down sometimes the strut assembly may need replacing.1996 Polaris Magnum 4X4 Service Manual PDF Download Sometimes a simple rerouting of the brown ground wires can solve problems if it's not mechanical related.