I have a 08 polaris sportsman 800 and it makes a clunk rattle noise when I let off the gas on flat ground or descending down a mild hill.  Need help in identifying this source.  My dealer says it is normal and it is built like a tank.  Dealer said it was the gears clashing together.  It's still under warranty for 5 more months. What is the noise and how can it be fixed.  If it is the U-joint in the drive shaft how can I fix the slack or clanking noise?????  

I am experiencing the same thing and have decided that it's rubbing coming from the clutch housing. I am not sure what I'm going to do about it yet.  

ok i just had to.....

that is the sound of the squirell falling off his wheel when you suddenly let off the throttle (seems those sudden stops just kill him)

and while going downhill he loses his balance. (yes he is getting drunk because of the embarassment and shame of being put into a Polaris, since his lifelong dream has to been to be put into a real atv.)

sorry i just had to, it was too good to pass up.

ok i'll be serious,
the only way i know of taking up the slack in the u-joints is to buy aftermarket u-joints, since the factory replacements are all designed the same way.

but there's no real guarantee that the aftermarkets will be larger.

i have done this once with the aftermarket u-joints and it worked.

this only works if the u-joints are the reason there is slack.

if the pinion gear or ring gears have slack in them you'll have to work on the ring and pinion gears.

it could also be that they gears in the transmission have slack in them.

there is no fix for this unless polaris decides to redesign the gearing, to my knowledge the only sourse for these parts is through polaris.  

I like the squirrel theory....and your probably right.haha..but I'm favorable to the Polaris....I took it to the dealer and they told me it was the gears.  The forums told me it was the u-joints.  I wish that someone with the right expertise could make it go away.  The sound that it without selling my new quad.  Besides that it is the best quad ever built.  Polaris just needs to tell it's buyers what the remedy for this problem is.  If anyone exactly knows please let us know and how to fix it and where to buy the parts from.  thank you.....  

I HAVE A 2007 500 SPORTSMAN WITH 537 MILES IT HAS A LOUD CLUTCH NOISE,REAR END NOISE THE DEALER SAYS ITS NORMAL.SO EVERY NOISE YOU HERE ITS NORMAL.YOU PAID ALL THIS MONEY FOR A NOISY ATV.I'LL NOT HAVE THIS 500 FOR LONG.  

Well, I've come to an end about the noise when I ride down hill while coasting even in neutral in two wheel drive.  My 08 Sportsman 800 still has a clatter sound no matter what you do. It does not matter if I'm in gear or in neutral there is still that annoying clatter/clashing sound between the clutch and the transmission.
Two dealers and a Polaris Rep advised me that is just the way it is...
Thanks for all your suggestions..I do not recommend Polaris Sportsmans if you want an annoying noisy quad. Buy a Honda....  

it's the sound of the gears clashing together.
the earlier pvt trannys' were alot tighter, but for the last 4 years the tranny's have had excessive slack in the gears, the gears slamming together will eventually cause the gear to break or wear out prematurely, but the dealer will not honor it under warranty because they are not breaking until after the warranty is out.  

Guys, I have a fix for this problem. Go to your local Home Depot. Look for the FOR SALE signs. Seriously, if a manufacturer tells you you are SOL, tell them goodbye and head to the Yamaha dealer. The Raptor 700 is a good bike. I am partial to my 660 and will keep it until it's beyond repair. I hope for your sake(s) that Polaris will take care of it's customers while it still has them. My brother has a 05 Predator, and his wife has a 330 Sportsman. They are good bikes, but his seems to have issues alot. It can be expensive and aggravating as hell.  

Ok guys Polaris says this is normal for the clutch and the transmission to rattle noise when you go down hill.  Someone mentioned on a post to try Lucas oil, which I did and added just a little and it helped the noise go away.  Now I can barely hear it.  Lucas Oil was purchased at Walmart.  Of course my warrant has ran out now.