Any Polaris 4WD Experts? I'm Disappointed With My Ranger 500 In Snow

[David_Kb7uns]

The Polaris ATV use a Hilliard clutch system in the front axle, the rear wheels are always pushing the fronts a little until they slip. when slippage occurs the drivetrain in the front catches up to a set of rollers in a cage. When the roller cage is restricted from movement by friction on a plate that is kept from moving by an electromagnet the rollers move up a ramp and bind. when the binding occurs the front wheels start being driven. Some Polaris ATVs have either a plastic cage or a metal one depending on when they were made. If you do jumping or engaging while wheels are spinning things can and will be broken. Most Polaris units have a lockout for engaging above a certain RPM or when out of gear. If your gear indication sensor is not telling what gear you bare in the 4WD usually will not engage. If things are indicating engagement and it is not happening chances are there may be internal damage with a bent armature plate, bad magnet or broken cage. Improper tire sizing will also effect engagement.

Exploded view of system
http://www.hilliardcorp.com/media/1...fferential-for-On-Demand-Four-Wheel-Drive.pdf

David Kb7uns

 

[biffnh]

I have a 2011 400 HO and I am very impressed with the 4WD system and how well it handles snow and ice. The only thing that seems to stop it is deep snow. Just don't shift to 4WD while the rear wheels are spinning, but on the fly is fine. I have 650 hours on my machine and only regular maintenance items so far.

 

[Milo]

Thanks. This illustrates what was I felt was contributing to the unstable tracking on ice and snow and the rear spinning up the surface of the wet trail going up a steep hill while the fronts were rotating at ground speed. IMO this Hilliard system belongs on a golf cart or maybe an AWD garden tractor to help prevent it from getting stuck but not on a ATV or UTV. Does any other manufacturer utilize this setup?

I just read through a long discussion of this over at a Ranger forum. They even posted a video that shows the 4WD drive engaged and the rear wheels turning at a faster rate than the front. Tires are marked and you can clearly see the front wheels rotating slower than the rear.
This is not what I want on a 4WD UTV.

 

[PapaPerk]

I have a 2011 400 HO and I am very impressed with the 4WD system and how well it handles snow and ice. The only thing that seems to stop it is deep snow. Just don't shift to 4WD while the rear wheels are spinning, but on the fly is fine. I have 650 hours on my machine and only regular maintenance items so far.

Great to hear! That's a lot of hours! I have a 2012 400 and really like it. Goes great in snow. Hope mine follows your track record!

 

[jimgerken]

I have similar experience with a JD Gator 825i UTV. The rear tires have to be spinning 5% faster than the fronts, for the fronts to get any power, when locked in 4WD. Apprently JD engineers decided this is the way it had to work with the components they had and the amount of stress they wanted the front drive system to experience. I have been told it works the same as a Subaru car. The problem is, when in snow the rears spin all the time. After using this machine a while, I decided to put tracks on it for snow use. When I looked in to tracks, I found out that Camoplast has a full range of sprockets, and will specify different sprockets based on your horsepower. Also, for the Gator (and others ???) they will specify two different size sprockets, one for rear, and different for front, to encourage the differential system that controls power to the front to supply power continuously. The tracks work well with this setup.
I think you could do something similar with tires SIZES. Size the front slightly different than the rear (or slightly different than original). This confuses the differential and causes it to deliver power continuously. It would take some experimenting. Fine tune it with air pressure. If you can find out what the magic number is (like the Gator is supposedly 5%), you could then calculate a tire size that could get you close. Check me on this, but I THINK that means the front tires must be smaller, but maybe I have that backwards.

 

[PapaPerk]

I have similar experience with a JD Gator 825i UTV. The rear tires have to be spinning 5% faster than the fronts, for the fronts to get any power, when locked in 4WD. Apprently JD engineers decided this is the way it had to work with the components they had and the amount of stress they wanted the front drive system to experience. I have been told it works the same as a Subaru car. The problem is, when in snow the rears spin all the time. After using this machine a while, I decided to put tracks on it for snow use. When I looked in to tracks, I found out that Camoplast has a full range of sprockets, and will specify different sprockets based on your horsepower. Also, for the Gator (and others ???) they will specify two different size sprockets, one for rear, and different for front, to encourage the differential system that controls power to the front to supply power continuously. The tracks work well with this setup.
I think you could do something similar with tires SIZES. Size the front slightly different than the rear (or slightly different than original). This confuses the differential and causes it to deliver power continuously. It would take some experimenting. Fine tune it with air pressure. If you can find out what the magic number is (like the Gator is supposedly 5%), you could then calculate a tire size that could get you close. Check me on this, but I THINK that means the front tires must be smaller, but maybe I have that backwards.

Subaru drivetrain does not work the way you describe. It uses 3 diffs... Front, center, and rear. Center is viscous coupler... It has ability to transfer power to front and rear based on traction conditions. Center diffs are required on road vehicles with awd due to each wheel turning at different rates. Any slippage of tires on dry pavement is a recipe for disaster on a road vehicle. In other words the front and rear tires do not operate at different speeds during normal operation... Of course the speeds can change during wheel slippage because thats how all wheel drive works.

As far as trying to fool the Polaris awd system into thinking the rear is slipping all the time... Good luck with that. Lol!

 

[Milo]

I have similar experience with a JD Gator 825i UTV. The rear tires have to be spinning 5% faster than the fronts, for the fronts to get any power, when locked in 4WD....
....Size the front slightly different than the rear (or slightly different than original). This confuses the differential and causes it to deliver power continuously. It would take some experimenting. Fine tune it with air pressure. If you can find out what the magic number is (like the Gator is supposedly 5%), you could then calculate a tire size that could get you close. Check me on this, but I THINK that means the front tires must be smaller, but maybe I have that backwards.

LOL I guess I was destined to end up with this set-up because the other UTV I had narrowed down to was a John Deere!

I tried that with air pressure. My thought was to make the rear tire diameter smaller which would mean the wheel would turn faster relative to the front. So I under-inflated the rears by 6 pounds and over-inflated the fronts of course that alone wouldn't make up a 20% difference. It was difficult to tell but it may have helped a bit.

 

[PapaPerk]

LOL I guess I was destined to end up with this set-up because the other UTV I had narrowed down to was a John Deere!

I tried that with air pressure. My thought was to make the rear tire diameter smaller which would mean the wheel would turn faster relative to the front. So I under-inflated the rears by 6 pounds and over-inflated the fronts of course that alone wouldn't make up a 20% difference. It was difficult to tell but it may have helped a bit.

Have you talked to dealer about it? If you run it with all fours in the air you should easily be able to measure rpm differences between front and back.

 

[Milo]

Have you talked to dealer about it? If you run it with all fours in the air you should easily be able to measure rpm differences between front and back.

No but I believe the response is "they all do that".

 

[johnk]

I have a 2012 Polaris 500 EFI UTV. Going side ways across a hill in the snow It is a mother to steer in AWD. It fishtails real bad with the rear always slipping downhill. I have great tires on it but my Honda Rubicon ATV really outperformed this UTV on sidehill slippage and downhill braking. Sure like the pickup bed and the SXS seats though that make up for it!