Went to hatfield McCoy last week and while coming down a steep grade in 4x4 ADC and could hear a grinding noise , does not do it out of ADC.has anyone had this?

 

My 07, the first of the ADC's has done that on a couple occasions when coming down very steep hills. I pulled my front drive, disassembled completely right down to where every part was laid out in front of me to inspect. I figured it was the dreaded cage issue but found absolutely nothing wrong. In fact most of the parts looked like new with only a couple showing very light wear marks. I did finally recreate the sound after some trial and error on some short but very steep hills and found that when the suspension is compressed hard, the front the axle shafts are nearly/if not horizontal pushing inward on the drive unit. The only thing I can figure is the pressure is causing some rub in the front drive line somewhere. I can't see what though ??? Now that I've installed some HD springs in front I figure/hope to never hear it again.

 

Before you worry too much about it and start tearing things apart, change the demand drive fluid in the front differential. You may have to change it a couple of times if it is really dirty, but a real good chance this will fix the grinding noise. Change it once and then ride a little. If it still grinds, change it again to flush everything out good. It only takes about 8 oz. to fill, so 1 quart will do several changes. The demand drive is very sensitive to dirty oil. Be sure to use the Polaris Demand Drive Plus oil when you change it. You may also need to bleed the ADC system as well. It uses the same oil. There are two bleeder valves, one on each side of the diff. They will bleed themselves by gravity. Do one at a time and be sure to keep the resevoir topped off while you bleed it so no air gets into the system.
If you haven't changed this oil before, I can almost guarantee this will fix your problem.

 

thanks, i,ll get on the fluid change today

 

Let us know if that fixes it for you.

 

changed the fluid twice and it was black, knocked over the bottle so i had to order some off E bay due to the fact that the nearest dealer is about 90 miles away and i have to work the next 5 days, but i'll get back on it next week as two times didn't get it. I'll get back with ya next week . thanks

 

have now changed the oil 5 times looks almost new coming out,but still have noise even on level ground, but the 4wd works fine, anbody have any ideas. thanks

 

I noticed a similar situation this weekend. After not riding due to some health issues and a hip replacement for a couple years I'm back on the wheeler. Where I noticed the condition is if I go slowly in wad, and let off the throttle the front end makes more of a clunking sound than a grinding. After I stop, and while sitting still if I take it out of AWD it clunks, and the whole quad sort of twists as if it were torqued a bit, and the torque is being released. On the trails I did notice the clunking sound when descending steep hills when the ADC was engaging, but no grinding sound.

 

I'm out of ideas. My 500 and 850 both have had the front end grind with the ADC engaged and changing the fluid has taken care of the problem in both of them. One last thought. Are you testing it on a paved surface, or on a surface where there can be a slight amount of wheel slippage? Locking the front and rear together like that on a hard surface can cause issues since there is a different gear ratio in the front than in the rear.
That's all I got. Good luck.

 

oldman800's story confirms a little more of what my dealer told me. They said it was due to the lack of using it. The more I used my ADC the more it "broke in". I really never used it since new until I got about 250 miles on it a couple years back and it did the same thing. Clunking, grinding, etc... We don't have much use for the ADC around here so I probably will never use it that much.