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i not 1 to put much faith in electronics that might get introduce to water & mud, so has any1 came up with a hub mod like this before?
 

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the engagement is mechanical. the only electrical part about it is the 12v power it throws to the gearbox to create a magnet inside the box.

I guess a should add on what year and model of machine?
 

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Discussion Starter #3
the engagement is mechanical. the only electrical part about it is the 12v power it throws to the gearbox to create a magnet inside the box.

I guess a should add on what year and model of machine?
ok i c now, the 12v power comes from the stator. so theoretically speaking if there is a short or break in the wire the awd wont engage? i'm a 1st time polaris owner as u can tell, i'm just trying 2 figure out how things work. it's a 96 scrambler.
 

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the engagement is mechanical. the only electrical part about it is the 12v power it throws to the gearbox to create a magnet inside the box.

I guess a should add on what year and model of machine?
ok i c now, the 12v power comes from the stator. so theoretically speaking if there is a short or break in the wire the awd wont engage? i'm a 1st time polaris owner as u can tell, i'm just trying 2 figure out how things work. it's a 96 scrambler.
I can go into much greater detail tomorrow, but you got the idea. All the AWD switch does is provide a magnetic field, that initates the front gearcase into an "overrunning" position. It has to do with the way things are geared, so you want to avoid changing tire size and sprocket sizes. When the front tires spin faster then the drive shafts would, the front gearcase is "overrunning" itself. The rollers in the cage are already indexed and ready to engage, they just arent engaged yet. On your older machine, each hub has a magnetic coil that provides two seperate sources of power. The newer machines just have one source of power. When the rear slips, the front wheels slow down to, and that causes the rollers to engage the the drive shafts and keep you moving. it really is quite mechanical. All you have is the 12v source starting the chain reaction of connections.

You can do what is called manually wedgeing the rollers so the gearcase stays engaged at all times. I copy and pasted below a letter so that you can see and hopefully understand what wedgeing the front is. Let me know if you have any other questions. I am happy to help you learn.

It is an e-mail straight to Hilliard corporation who supplies Polaris.


I wrote to Matt Cowen, the Engineering Product Manager at Hilliard Corporation and asked a few questions about the Hilliard Overrunning Clutch used in the Sportsman ATV's.

First my questions, followed by the response from Hilliard with their permission to share the information:

1) I regularly engage the AWD clutch for 4-wheel engine braking by causing the rear wheels to slip in reverse, stopping, then putting the machine in forward before descending the hill. Will this harm the clutch at all?

2) When I perform the above maneuver the clutch remains engaged, even while powering forward, until I switch off the AWD engaging coil. Is this normal operation for the clutch?

3) Is there a way to engage the clutch prior to wheel-spin, allowing me on-demand AWD?

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Mr. Anderson,

The condition that you are asking about above is called "wedging". What you are doing is locking the rolls in the reverse profile of the clutch (it is a bi-directional clutch set-up) and proceeding in the forward direction thus not allowing the clutch to overrun (which is the normal condition). This in turn locks up the drive train and makes the system steer like a fully locked differential. This condition is

Advantageous if going down a steep hill because it will only allow the front wheels to move as fast as the drive train. This will fully utilize the engine brake because when going downhill the weight distribution of the bike goes to the front end and that is where you want the majority of your traction.

This "wedging" will not hurt the front gear case, but it could accelerate the wear of the drive train components (such as the front prop shaft) because it does completely bind up the system and the bike will be very difficult to steer. Because of the binding and additional steering effort, neither Hilliard nor Polaris will recommend doing this.

You can get the system out of the "wedging" condition without turning the power off to the AWD system, but it is very difficult and not always repeatable. The only true, 100% way to release the clutch is to turn the power off and put the bike in reverse. This will release the pressure on the clutch and the springs inside the clutch will return the rollers back to the neutral position.

To answer #3, there is no way to drive the front wheels at the same time as the rear wheels without the rear wheels slipping. The bike is geared to have a 20% speed difference from the back to the front.

This means that it takes the rear wheel to slip or spin 20% (1/5th of a rear tire revolution) before the front wheel to drive the system. This is necessary to give the bike a tight turning radius and to prevent the bike from automatically "wedging". If the front to rear ratio was 1:1, every time you turn the handle bars even slightly, the front wheels would act like they have a fully locked differential and it would take you 30 feet to turn a 90 degree turn (like driving a new Kawasaki Prairie with the front gearcase locked). Because when you turn, all of the wheels on the bike are now moving at different speeds dictated by the ground speed, and the front clutch would not be able to overrun. With the 20% speed difference, the AWD can be on all the time and it will only be there when you need it. You won't get any of the side effects of all the other systems that don't allow you to turn the 4wd on and off. Basically, having the front wheels driving the same speed as the rear wheels would be like driving a tank and would be hard on the arms
and not very fun.

I hope I have answered all of your questions and not confused you to much. Browse through the overrunning clutch section on the Hilliard web site (Hilliard Industrial Clutches, Brakes, and Oil Filtration) for more info on how overrunning clutches work if you have any more questions. Have a good day.

Thanks,

Matt Cowen

Engineering Product Manager

Drive Train Products

Hilliard Corporation


phone: (607) 733-7121 ext. 376

fax: (607) 733-1045
 

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Dont feel like you have to ask me. :)

Lots of great guys on the boards will all sorts of different knowledge bases. Dont be afraid to ask any questions though, we are all very happy to help answer anything you might have. Nobody will make give you a hard time about. We are just glad to have you on board and welcome as many questions as you can possibly have.

Just as elermkit said!
 
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