Hi guys,

I have a 2008 Scrambler 500 4x4, everything works on it perfectly, except the 4wd when in reverse.

Now, it DOES work, but it's kind of a pain to get it to engage.

When I put it in reverse (holding down the override button obviously), 4wd will not work unless I rev the engine a few times, where the rear wheels will spin, and then randomly it will engage the fronts and work from then on (although sometimes if I let off the throttle it will disengage the fronts again, requiring some more revving for it to engage again).

I have changed the oil in the front hubs, not sure what else to look for considering it works fine in forward gear, and does also work in reverse, but need to rev it a few times to get it to engage.

Also, the override button seems to be functioning correctly as well, considering if I hold it in I can go to higher speeds in reverse without it cutting the ignition.

Anyone know what wires I can disconnect to bypass the override switch in the mean time for testing.

Thanks

 

You can unplug the rev limiter which should be a little black box under the hood. What kind of hub fluid are you using?

 

Hi Frank

You mean just unplug the whole box altogether? I disconnected a gray/orange wire and that stopped the limiter, but still had to push for 4wd in reverse. I see now some other wires need to be connected together for the 4wd to work without the switch.

As for the fluid, I'm not sure as it was quite a long time ago... It wasn't Polaris fluid, just some synthetic gear oil I believe.

Edit: after reading now, it seems that the fluid needs to be quite thin. Honestly I don't remember what I put in as it was years ago (only ride a few times a year), but as I said, it works perfectly going forward, would it really make that much difference in reverse? It seems using ATF type F is acceptable in the front hubs, so I will try putting that in.

 

AFAIK the only fluid you're supposed to use is Polaris Demand Drive Fluid, which may also be labeled Demand Drive Plus. They changed the name once or twice. Another company, like Amsoil, might make a substitute fluid but I never used anything other than the Polaris fluid. It's not like engine oil or gear oil, where everyone makes it and any brand will work. ATF might work, but I'd only use it in an emergency and change it the first chance I got. I think Polaris used ATF when they first made ATVs, but my '97 Sportsman 500 took demand drive fluid. If I had something older than that I might try ATF, but I know demand drive fluid works. Like it says on the bottle, for HUB & centralized Hilliard clutches. But It's your money to spend as you see fit. The wrong fluid can cause problems. That's why I asked.

ETA: Yes you can just unplug the whole limiter module. You won't have to push the override button to get full power in reverse. I'm not 100% sure, but I think you still need to push the button to get 4WD in reverse, because that's a separate function.

 

Polaris actually recommended using ATF for many years as an alternative to Demand Drive Fluid in all their service manuals. They really like selling hydraulic oil in a fancy Polaris bottle for $12 a quart so now they don't. ALL Polaris fluids are just over priced regular products in slick Polaris packaging. There is NOTHING special about them. Any good quality oil with the appropriate specs for the intended use is just as good or better than the Polaris branded products. Polaris doesn't make oil...Oil companies do. Polaris just sources it out from suppliers who put it in Polaris packaging.

 

So what are are the specs on demand drive fluid?

 

Its just a 10w hydraulic oil like ATF.

 

Thanks guys. My uncle had some Demand drive fluid from his Sportsman so I'm gonna try putting that in in the next few days to see if there's a difference or not. If not, not sure what else I should look for, any ideas?

 

Some Polaris front gearcases do have clutch plates that need demand drive for the anti chatter additives. That would be ADC or active decent control. All need the thinner oil to be able to release the electromagnetic clutch easier in cold weather when not engaged but also have gear oil capabilities for the ring and pinion. It has to be pretty old to use 90 wt in the front gearcase like 02 and prior. Hope this helps.
I forgot to say I think your over ride switch contacts need to be cleaned or replaced. Water tends to collect where that switch is and can corrode. I have taken them apart otherwise the assembly needs replaced. Verify first.

 

Thanks. It's a 2008 Scrambler (has the magnetic hubs) so it does use Polaris front gear case lube (or 75W-90 GL5) in the front diff.

Good call on the switch, I'll check it out, even though when I press the button 12V is applied to the hubs (tested it myself).