Last night I went on a short ride to find some mud holes to try out my new AT589 tires. I found a hole about 20 to 30 feet long and about half way thru I was boging down somewhat but still moving and the whole left side of my wheeler exploded! It was a force great enought to blow off the clutch cover and the side body panel. It was dark and I was able to fine 1/2 of my front drive (split into several pieces). I know I should have been in low range, but I was in high. My new tires are not oversize. Is this something anyone has ever seen before? I thought the worst thing that could happen in this case would be a smoked belt. I could not even find a weight or the spring left over. Any ideas?

 

I agree 100%, you should have been in Lo range especially with 589s. They grip 300% (my guess) more than stockers so it is very important to use Lo. Having said that I agree with you again that using Hi instead of Lo should not cause it too explode. If you use Hi too often you will groove the clutches and destroy the belt. I would have to think in your case something came loose or broke causing the whole assembly to self-destruct.
The most important thing is you weren't injured which could have happened very easily considering the failure. All mechanical parts can be replaced even though it maybe expensive.
Good luck with the repair. If you need any instructional help with the repair you know how to reach us.

 

Riding in high range alone will not cause that to happen. For the clutch to come off the crank, I would think that either the bolt that holds the clutch assembly to the crank came out (or broke) or the clutch shattered allowing it to come loose. In the second instance, I would think that the bolt that holds the clutch on would still be threaded into the end of the crank.

Please post your results when you find out what happened b/c that is very uncommon.

 

I would think it would had to have been a weak casting or the bolt coming loose. You have to wonder considering the race modded ones are turning close to 8000 rpms and get rode really hard.

 

The bolt is still in the end of the crank. The inside half of the pully is still there. If I can figure how to post a picture, I will show the parts. It's ugly. The outer half of the assy. (the part with the springs and weights) is what busted in half. It pull all the cover screws out of the back plate too. Think that is toast also.

 

The only thing that being in high would have done over low is allow the belt to slip and heat up the clutch, which would've helped it blow sooner but regaurdless it would've blown anyway. The reason would've been simply a clutch that had a crack in the sheave from factory unless it was a pretty old machine with a lot of miles on it. Your very lucky that a peice of it didn't fly up and hit you. I've seen Snowmobile clutches explode and they are turning why more RPM's and using a lot more force the ATV clutches. That's why I say the clutch had to have been bad from the start because ATV clutches don't see that harsh of conditions.

 

I have heard of this happening before on a SP500. One of my former co-workers tornadoed his clutch as well. He showed me pics and it was ugly. There were pieces of the clutch coming out both ends of the cover. It was a casting problem if I remember right. I don't remember the name of the dealer who fixed the machine after this happened, but I think it was in Deer River, MN.

 

Anyone want to see what a exploding clutch can do, drop me a note and i'll send a picture. I tore it down this morning and it knocked a hole in the driven clutch as well as the oil filter. I thought the screws had stripped out of the back plate that holds the cover on, but it busted the back plate everwhere it was connceted. I was lucky not to get hurt.