When I brought a second hand engine from eBay the nut was corroded so bad onto the drive shaft that even with a long bar or high powered impact gun the rear wheel was slipping despite full force on the brake. In the end I got a grinder and cut it and it came off easily. I think a combination of the heat and weakening the nut released it, just be careful not to cut too close to the drive shaft and end up damaging the threads. This should only be necessary for the most stubborn of drive nuts. I also prematurely damaged my chain putting so much stress on it during the original attempts to remove the nut and had to replace it shortly after.

https://s12.postimg.org/jzt5sm0m5/nut.jpg

Wow that's impressive were they the original OEM ones?

Hi my original chain and sprockets lasted 13000 miles as well, I think it would have lasted longer but I forgot to lube it for the return leg of this years xt660 meet total trip 640 miles for me.:eusa_doh: