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Discussion Starter #1
Hello..... I have a 05 Sportman 800 EFI that is not locking into 4 wheel drive. When the 2 x 2 to 4 x 4 switch is activated the gauge will show the 4 wheels as in 4 wheel drive however the front wheels will not engage. Whether in High or low gear. I placed the machine on blocks engaged the 4 wheel drive and the drive shaft coming from the engine foward is not turning the rear is working fine. In fact the bike runs excellent short of this issue. I am under the impression from research there is some sort of soleniod in the front differential that may be bad. Please advise as to how to repair so that I can eliminate the laughter from my buddies when I get stuck! Thanks!
 

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Welcome to the board!:trink26:
 

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Yes, welcome to the forum, and congrats... you are officially the 1,000,000 person to have issues with the Polaris AWD (including me). LOL

Seriously, the front drive shaft should turn. You might have stripped the yoke on the shaft. I would check that first if the AWD is coming on your dash and the speedo is working.

Good luck.
 

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Front shaft spinning? If yes, check the oil in the final drive, the wrong weight oil can cause non 4wd engagement. Otherwise it may be an electrical connection on the diff. Try that first.
Cheers mate.
 

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When you say block, do you mean all 4 wheels off the ground? The rear wheels need slip before the fronts will kick in. If the sensor doesnt detect a rear wheel slip, the fronts stay disengaged.
 

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This is a large misconception about the Hilliard system that Polaris uses. There is NO speed sensor that detects slippage. The Hilliard system is sort of... an overrunning clutch. My buddy works on these machines (A LOT :D), and here is how he explained it to me...

With normal riding where there is enough traction to keep the rear from spinning and the gearing is set up to keep the front axles turning faster than the ring gear carrier.

The front is geared to turn a little SLOWER than the rear. In essence, the front axles overruns the the carrier and it turns faster than the carrier as they spin the same speed as the rear wheels. This keeps it OUT of AWD until the rear slips. Once the rear slips the front ring and pinion gear carrier meets axle speed and engages the front axles to the ring
gear carrier mechanically and locks it in AWD. If the front and rear were geared the same it would in and out of AWD all the time.

So, if the wheels are OFF the ground, the rear wheels will spin faster than the front wheels (because it is geared slower) and should engage AWD.

As I said previously, if the AWD switch and speedo are working and the front drive shaft is NOT turning, then the front drive shaft is not engaging... possibly stripped.

Somewhere I saw a good video of the difference in wheel speed when all the wheels are spinning on the ground, which will show the difference in gearing. I'll see if I can find it.

Here we go...

 

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Discussion Starter #7
I appreciate the responses!!!!! I am going to change the Diff fluid and check electrical connections....... Thanks John
 
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