HELP!!!!!
I was riding my (totally scratchless) '94 sportsman 400 20th anniv. model yesterday in deep snow when my left front wheel stopped spinning.
I checked the drive shaft from the bottom of the mcpheerson to the drive housing in the front and the shaft turns... but the hub, disc rim and tire don't.

what happened???

 

it's the C.V., ain't it?
just tell me... i can handle it.

 

The 20th anniversary must be for Polaris since they haven't been making quads that long in '94. Anyway to answer your question: If there were no popping noises or jerking in the handlebars, your cv joint is not gone. There are 2 possible things that could be wrong. One, you're either not getting power to that hub, or two, something is wrong with the internals of the hub. Changing the fluid might solve the problem (go ahead and change it in both hubs). If that doesn't fix it, you might want to look for the wire that comes in the back side of the strut, and follow it up as high as you can, making sure it isn't broken or worn through. If that looks good, I would take off the hub cap and take a look inside there. It could be as simple as a bad spring inside the hub. Anyway, hopefully someone else will post with more information, but what I've suggested is a good start.

Waylan

 

I have found this web-site very helpful in taking things apart....FRONT HUB

 

There are two copper washers that act like coils engaging the front hub,Replace them 4 bucks.Get with a guy named surfersam he just replaced his on a 500.

 

As Walexa says, focus on two areas, electrical and machanical.

Mechanically speaking, your front driveshaft and front axles will always rotate (in 2WD or 4WD). If you busted your CV joint, you will most likely hear popping noises as the front axle turns (in 2WD or 4WD).

The front drivetrain is pretty simple. The axle always turns. The axle goes through the strut assembly and into the middle of the wheel hub. The wheel hub rotates freely in 2WD. The wheel hub is engaged in 4WD electrically (when you push the AWD switch) by means of a magnetic coil in the strut assembly and a rotating armature plate inside the hub. The armature plate enagages a clutch assembly that has a cam that is toothed to the axle spindle. The armature plate and clutch assembly rotate with the axle in 2WD. When the magnetic coil is energized, the armature plate is attracted to the magnetic coil in the strut and it stops spinning. The armature plate stops spinning long enough to cause the outside roll cage of the clutch assembly to stop rotating while the inside cam of the clutch assembly continues to turn with the axle spindle. The high sides of the cam roll up and push out the 6 rolls inside the roll cage. These rolls "swell" out and contact the hub (Remember the hub rotates freely in 2WD but not in 4WD). The clutch assembly "swells" and causes the clutch assembly to lock the hub and axle spindle together.

What to look for:

I. Electrically,
1. Are you getting power to the magnetic coil? Check for broken wires, bad connection, etc.
2. Disconnect the magnetic coil wire from the wire block and "Ohm" it with a multimeter. It should read around 27 Ohms.

II. Mechanically,
1. Drain the hub fluid and replace. Low hub fluid or dirty hub fluid can cause the armature plate or clutch assembly not to engage.
2. Inspect the armature plate for bends and wear. They must be flat to work properly. And they are cheap to replace.
3. Inspect the clutch assembly. The cam and rolls/roll cage should move freely without any binding. If you had a fluid leak, the rolls could have been marred from lack of lubrication. Check the garter spring. The spring keeps enough tension on the rolls to stop them from engaging when not in 4WD. Too much tension and the rolls won't reach the surface of the hub. Replace if in doubt.
4. If you have recently had work done on the hubs or struts, check the pole gap between the magnetic coil and the armature plate. The adjustment is made by moving the magnetic coil closer to the armature plateby tapping the seal outward/inward. The gap should be approximately 0.001 inches.

I may have missed something but this should get you started.

SurferSam

 

the spring was busted.
Tannx for the brain work.

you people rule!

i'm slowly learning that this thing ain't a jeep, it's a Hum-V.

 

Glad to see it was one of the cheap parts.

SurferSam