Ranger 900: Broken Front Differential

[Howland36]

That sucks, i really wish polaris stuff would hold up better because there is somethings i really like about them

[Fabricator]

Thats just a new rig, is that part covered by the dealer, warranty.

[_Nutts_]

WOW Chris, that's a bummer !!! You take great care of your machine and to have a failure like that is just crazy. If it makes you feel any better I just dropped $1300 plus in my Teryx.

JBS/BKP Powered Teryx4 750

[Yotehunter66]

That's harsh. Hope you can repair it.

[Chris]

Today I opened the front differential up, and things looked good inside. When the pinion bearing failed, some of the ball bearings went inside the diff and wedged themselves between the ring gear and the case. Luckily, the pinion gear had left the building. If there had been driving force on the ring gear, I suspect even more massive carnage would have ensued inside the differential. A new pinion bearing and a new pinion seal should get the front differential fully operational.

But you know I cannot leave well enough alone!



I'm taking this opportunity to upgrade my front differential to the new close-ratio AWD differential Polaris has recently started using. The RZR models refer to this as "High Performance True ON-Demand AWD." The 2016 Rangers call it "Pro-Lock On-Demand AWD."

This is a bunch of Polaris marketing speak for, "The front are rear ring and pinion ratios are closer." The Polaris AWD system works because the front differential isn't technically a differential. It's an over-running Hilliard Clutch. The front differential has a numerically lower ring and pinion set than the rear differential. So you end up with the rear pushing the front end. The Hilliard Clutch lets the front tires free spin faster than the front ring gear, but not slower than the ring gear. When the rear wheels slip enough to overcome the gearing difference, the front wheels will then be driven by the ring gear.

The positive of this system is that it will pull all four tires whenever the AWD switch is selected. When the rear tires slip, the front will pull. When the rear tires regain traction, the front tires go back freewheeling. The negative of this system is that the driver cannot physically lock the front and back tires together. The other big negative is that the front wheels turn slightly slower than the rear wheels in low traction situations where the AWD is actively sending power to the front.

How much slower do the front wheels turn than the back wheels?

Take a look at these ring and pinion ratios:

Standard Polaris Ranger 900 AWD
Front 3.82:1
Rear 2.96:1

Polaris Pro-Lock Ranger 900 AWD
Front 3.08:1
Rear 2.96:1

The numerical ratios show that Polaris narrowed the gearing spread. It's still not 1:1 like you'd find on a Yamaha or Kawasaki or your trust 4x4 pickup. It's still technically an On-Demand AWD system and not a On-Command 4WD system. However, by making the ratios closer the front wheels should help pull more. Coming out of a corner under throttle should be better as the front wheels will help pull out of the corner. Similarly, all those of you who live in the frozen northern territories north of Dallas,TX should see better handling on snow and ice...LoL



I'll post up my thought and review of the new close ratio AWD setup when my new differential is delivered.

[Chris]

Polaris High Performance Close Ratio AWD

In a word: this is how the Ranger 900 should have come from the factory.

The standard Polaris AWD has its place, and it isn't necessarily bad. However, the close ratio AWD is simply better in every way. The front wheels drive almost the same speed as the back tires, not 20% slower than the back tires. In muddy ruts, the back end of the Ranger doesn't want to "dog track" and slide sideways into the ruts.

[WV Hot Rod Rhino]

Nice...that was weird

hotrods trails

[_Nutts_]

Glad to see its back running again !!! Hopefully the new diff holds up better than the last one.......

JBS/BKP Powered Teryx4 750