Hey guys,

I own a Grizzly 660, and am trying to explain to someone that has a Polaris how the Polaris AWD works.

He claims that the rear wheels do not need to slip to get the front's to engage. If I recall correctly it requires 1/5th of a turn to get the fronts to engage. Is there any credible articles that prove this?

Also, if you were to put a polaris on jack stands, with all 4 tires off the ground, then shift it into AWD, would the fronts spin?

Thanks much!

-Jared

 

If you put it on a stand and put it in all wheel drive all of the tires will spin. I dont know how much the tires have to spin to engage the AWD but I know it is not much. The polaris machines are what is referred to as true 4-wheel drives because both front wheels pull all of the time if the rear wheels slip, compared to some others that have limited slip and one front wheel will spin while the other sits still.

 

I guess I don't understand. If all 4 tires were off the ground, wouldn't it think that there was traction to the back tires, thus not letting the front engage?

Anyone else?

-Jared

 

I dont know why they all spin when you have the quad on jacks, but I have heard that they all do spin. But one example of true 4WD, if your chain breaks (like a friend of mine's did) you can ride your quad just using the 2 front wheels. Its a weird feeling, and I wouldnt recommend it, but its doable. [img]i/expressions/face-icon-small-smile.gif[/img]

 

It only makes sense that all 4 would spin on a stand. The back tires turn, the fronts don't, so the awd engauges to get traction. If you're in mud the same exact thing happens.

 

If it is on a stand and you put it in AWD and hit the gas in forward gear the back tires spin. That sends a message to the computer telling it that the rear tires are not getting any traction. The front tires will then engage and pull as long as you are on the gas. You can ride the polaris AWD quads without the rear chain but it is pretty rough on the front end to be doing all of the work. In the mud you can't beat the polaris quads. We have some mud bog races around here and if 5 polaris quads enter they will take the top 5 spots. Nothing else comes close in the mud.

 

The front drivetrain on a Polaris AWD works like this:

The front axles always turn, in 2WD or AWD. In 2WD the front axles are not "hooked up" with the front wheels and are spinning freely inside the front wheel hubs. But, it still turns the same amount as the rear axle. The front axle goes from the front differential through the strut assembly housing and into the middle of the front wheel hub. For sake of explanation, let's call the front wheel hub, front wheel rim, and the front tire the front wheel assembly. And let's call the rear wheel hub, rear wheel rim, and rear tire the rear wheel assembly. The front wheel assembly rotates freely in 2WD. The front wheel assembly is engaged in 4WD electrically (when you push the AWD switch) by means of a magnetic coil in the strut housing and a rotating armature plate attached to the axle inside the front wheel hub. The armature plate enagages a clutch assembly that is also connected to the front axle. When the magnetic coil is energized, the armature plate is attracted to the magnetic coil in the strut housing 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. The high sides of the cam roll up and push out 6 roll pins inside the clutch roll cage. These roll pins "ride out" and contact the front wheel assembly (remember the front wheel assembly rotates freely in 2WD but not in 4WD). The clutch "swells" and causes the front wheel assembly and front axle to bind together. Voila, you have AWD. To disengage AWD, you de-energize the magnetic coil by pushing the AWD button. Sometimes, it's necessary to let the quad roll backwards a bit to release the pressure from the clutch so the roll pins can retract.

Remember the front and rear axles turn the same revolutions, in 2WD or AWD. However, for the AWD to engage properly, the front axle must turn more than the front wheel assembly. The only way for this to happen is for the rear wheel assembly to turn more than the front wheel assembly. In real life, the rear wheels must spin momentarily before the AWD clutch assembly can swell. On jacks, the rear wheels must also spin momentarily before the AWD clutch assembly can swell.

Hope this understandable.

SurferSam

 

Great job of explaining. It shed light on something I didnt know about. I have noticed that sometime when turning off the AWD, ONE wheel in the front stays engaged, thus making me take off to the left or right depending on which wheel is locked in. Much like a bird with one wing would fly in a circle, or a frog with one leg would swim in a circle, etc. [img]i/expressions/face-icon-small-smile.gif[/img] Does this happen to anybody else?

 

[img]i/expressions/face-icon-small-happy.gif[/img]

Hello Surfer Sam,

Your response wasn't to a question I asked, but I would like to thank you for an excellent answer. It was well written, and if it's correct, which I can only assume it is, then give yourself a gold star.

Scott[img]i/expressions/face-icon-small-happy.gif[/img]

 

Thanks for the kind words. I've torn apart and rebuilt the front end on the Polaris a few times. In order to troubleshoot AWD problems, it helps to understand how the AWD Hillard clutch system works. With that said, I think I can offer m3kgt a few things to troubleshoot.

If one or both wheels do not disengage from AWD:

1. Check your hub fluid. If it is low, fill it and see if the problem resolves itself. Depending on how much you add or how often you have to add fluid, you may have to replace your wheel hub seal. Polaris hub fluid is recommended. Type F automatic transmission fluid is okay, too. Use synthetic if you can find it. Type F is recommended because it is thicker than the other ATFs.

2. Check the armature plate/magnetic coil. Check the armature plate for bends. Most "bent" points will be evident by a shiny worn spot on the plate. Check the armature plate for magnetization. Sometimes, the armature plate will develop a magnetic charge and will cause the AWD to stay engaged after the magnetic coil is de-energized. Replace the armature plate in either case.

3. The spacing between the magnetic coil and the armature plate is important. The pole gap tolerance is 0.000 inches to 0.001 inches. Consult a manual for measuring the pole gap. I think this scenario is an unlikely cause but check it if nothing else works.

4. If you at are a dead stop and you turn on the AWD switch: Then you hammer the throttle hard and launch the quad with a lot of torque, you cause the AWD clutch to lock in really tight. When you disengage the AWD and move forward, sometimes the AWD clutch can't unbind itself from the wheel hub. If possible, avoid pegging the throttle from a dead stop when you first energize the AWD. Sometimes you can't avoid it. You can disengage the AWD by rolling the bike backwards a bit to take the bind off the AWD clutch before going forward. When automatic locking hubs for trucks and SUVs first came out, you were instructed to shift out of 4WD and then drive in reverse to disengage the auto locking hubs. The AWD is similar.

Good Luck and post a follow-up with your findings. The forums are great for this kind of stuff. Chances are someone has an experience or solution to share. The only dumb question is the one not asked. I ask plenty.

SurferSam.