I have had chronic problems with my 2000 Scrambler 500cc. The chain keeps coming loose and in turn breaking. I am on my 3rd chain. Dealer has no clue, but did say they had another Scrambler in with the same problem. Each time they fixed the chain it loosened dangerously within 2 hours of riding. My warranty is nearly finished, unless I get a definitive answer and solution I am selling my quad. The last 4 times I have ridden I have been towed in. I can't take it anymore. It is a lemon. HELP.

 

Make sure they are torquing the 4 adjustment bolts to the specified settings. Just because they are a dealer doesn't necessarily mean the mechanic is following the right procedures.

 

One word "SHAFT" I owned a sport,had the exact same problems,but when mine broke for thr 3rd time it also cracked the bottom of the gear case.Make sure your not leaking oil!!!I took it off,which was a big pain,and had it welded and traded it for a mag 500.The mag might be a bit slower but gives me peace of mind..And so far not a thing has gone wrong

 

I would take the axle carier out and inspect the axle housing for imperfections and also the swing arm where it holds the housing. There could be some weld built up in there or something thats causing it not to be held properly. Also make sure its free from any grease that may be on it. Then assemble, adjust your chain and make sure its torqued to the correct setting as keven said. I think its 60 FT LBS. The Mechanic at the dealer stressed this to me. Then I would mark the housing and the axle carrier to see if it actually does move and how much. If it doesnt move then your chain is whimpy and you need to get some thing like a "SideWinder" chain. Or check the bushings in the swing arm for looseness. Thats about all there is back there. Dont sell it yet, there is something not right, just need to figure it out. Hope it helps. GJ

 

I dont know what you do with your scrambler but my brother in law has brike his chain twice this month and everytime it has been while he was jumping, its just to heavy. Good luck with whatever you do.

 

I had a problem just like that, and my dealer did not find the problem either. Turned out to be that one of the axle bearings was going out, letting the axle move forward and back on one side, causing "mysterious" chain problems. To find out if one (or both) of your bearings are roached, jack up both rear wheels and grab the axles (left hand-left axle, right hand-right axle) and try to move them forward and back (one side forward and other side back).
Ron

 

Mine kept loosening too and i eventually ruined my output shaft sproket. I replaced the sproket with an aftermarket unit and adjusted the carrier till the chain was snug. I then marked the carrier and swing arm in the optimal position. I then tightened the carrier bolts as tight as i could. I don't care if i break the bolts because i bought spares. Becareful not to tighten the brake assembly bolt too tight because it may strip. No problems since.

Chris Picciotto
99 Scrambler 500