does it make this noise going around sharp turns? forward or reverse? i just encounterd a noise that i thought was the rear diff on my 650, come to find out its the left rear outer cv joint when i back up or take tight turns it makes a pretty loud snapping noise,similar to a front wheel drive car when taking corners,so i pulled the axle out and disassembled the outer cv joint come to find out the inner ring is wearing out causing the 6 ***** inside to bind,and when forced they make a snapping sound.hope this helps

 

That sounds exactly like my problem...mine only does it when backing up and letting off the throttle. I wasn't sure how to take the outer cv joint apart, so I rotated the shaft in a circular pattern to see if there were any rough spots, but found only a very little spot that felt even remotly rough.

 

I found the same symptoms in a sportsman once, Popping only in reverse, noticed it after sitting for a month or so. I was able to determine the noise comeing from the left rear side. I was thinking it may have been the rear diff. bearing, but didnt want it to be that so I thought I would look at the easier things first, so I pulled the outer cv boot, it looked good. Then pulled the inner cv boot and there it was, the grease looked like mud. Apperantly at some point water had gotten in and started rusting things and after running it for a bit it mixed all the rust w/ the grease and made some nasty looking grud.

I'd check that before just riding it and seeing what breaks, maybe what ever it is could still be salvageable instead of being stranded and haveing to spend some serious cash to fix what ever the problem is and anything else that might be damaged when it goes.

good luck.

 

well mine now will only make the noise when backing up and taking tight turns, as far as taking it apart they are very simple to do on the independent suspention, pull the wheel then remove the cotter pin on the big axle nut, remove the axle nut,then take the upper control arm bolt out ,top of the rear hub, then grab the hub and pull away from the bike,now grab the axle from the inside cv and give it a slight tug , it should pull right out, remove the band clamps on the outer cv slide the boot back grab some rags and wipe away the old grease, i think you will find if you hold the axle and pull back and forth on the outer cv you will have play in the cv, and if so its getting worn out,

 

I had a poping noise coming from my 2003 AC 500i if I got on the bike and rocked it back and forth hard I could get it poping. I brought it to the dealer and he first replaced the baring it was ok for about 25 miles and came back. He then replaced the baring housing all has benn good for the last 600 miles so it may be the housing that is bad.

Bob AC 500I

 

its is the bearing in the hub cat has a bulletin need to remove bearing and add brown lock tight or bearing
lock tight and reinstall bearing will fix popping noise in rear hub causing is bearing moving in hub assembly