I am not a polaris owner....

I was riding this weekend and came across a guy stuck in the woods with a sportsman 400...with the pushbutton 4 wheel drive...

He was having trouble getting it to engage into 4 wheel....So I asked if I can help....anyway...we dug him out and got to talking....

Can someone give me a brief explanation of how the front wheels engage? ....This guy went into this long story about a magnetic engagement system....It just did not seem right......Even after looking at it.

I am not new to quads....Polaris...Yes... A simple explanation would be great...Because it almost seemed like this person was talking in circles.

 

ok,
if the button is pressed, when the rear wheels start to spin, the fronts engage... If hes in reverse, he MUST also press the OVERRIDE button to engage the AWD.
They use speed sensors... and a magnetic hub to engage the 4wd...
But it has to sense the rear wheels slipping first.. Thats why Polaris AWD doesnt slow your front wheels down on downhills..

 

The axle shafts have a small clutch assemblies keyed to them. It uses rollers that wedge themselves to the wheel hub when the clutch is held by the magnetic coil. The coil really only engages the clutch, once its engaged the wedged rollers provide all the holding power.
When in reverse the axle turns the opposite direction, it briefly unlocks the hub and then the rollers become wedged again. The reverse over ride button has to pushed to power the coils in reverse.
The speed sensor is meant to prevent hub engagement over 3000 engine RPMs. It gets its signal from the stator signal.

 

thanks for the reply guys....It was helpfull.

Makes much more sense now.

 

Charlie; What would happen if you entered a spot you needed 4wd unexpectedly, with the hammer down to keep forward momentum up you say 4wd won't engage until rev's drop below 3000rpm, what then at 2900 with rear wheels spinning furiously the front decides to engage, that must hurt!! I must admit I do not understand this system so please try explaining again.

 

The engineers must have figured that 3000 hurt alot less than 6000 RPMs. The system is pretty tough and they must have gernaded a few till they got to a point that they held together and thats where the module was set at. Also this is just on late model ATVs like 99 and up. I myself have never seen one damaged by this but I understand it snaps axle shafts. The biggest problem I have seen is loose spindle nuts and the oil leaks outmaking a mess out of the brakes.

 

Dear sayit_fmf
the sys is really simpler than one thinks.It will and does work at any rpm but you do have to use override button in rev.take note the 4-wd sys is same on scrambler models.As to harsh engagement no there is approx 1/16 of actual axle rot.before hubs should lock [ note never said can't fail but usually from dirty fluid in hubs ] The sys is true 4-wd if working as designed. Also i do not think polaris designed it our gov't did a long time ago for use on military truck's . what ??
any way the sys uses a part called hillard clutch
picture if you will a simple [ nut ] 6-sided oct shape.take a rather large dia nut place a pencil on all 6-sides grasp around the outside of all 6-pencils with one hand Reach in the nut with one finger of opp.hand and twist nut you will see how polaris hillard clutch sys works.one exception the factory has much better choice of materials.
have fun trying polarman