I was working out in some trees (tree farm) riding around a yamaha timberwolf. I would guess that i've put about 2 hours on the machine sence it's been on the farm. Went over to it, got on and put it in gear to be greated by a loud clunk, and the bike jumping forward, and repeate. I thought the drive shaft went out, luckly the reverse was still working so i got it back to the yard then left it there for a few days.
Got it loaded up and back to the shop and started tearing into the machine today. Got the thing apart just like i though, pretty simple (wish the 900 was that easy) and got the shaft and coupler out. Both look real good, nice and tight fit, every thing is fine on that end.
The final drive is another matter. A seal or something went out on the drive, and leaked oil into the swing arm, but not outside of the machine, at least enough to be noticed, but dust was getting into the final drive. Interesting thing happens, makes something like a grease. The end of the story so far is that the final drive is toast, and a new one is about $500, the ring and pinion is $250.
Now onto the lesson that i learned: Change the final drive oil every year. I got to thinking about it and the amount of dirt that was getting into the drive had to be pretty small, machine wasn't run often, and not much could get in at any one time. So if the oil had been changed at the anual rate the buildup of dirt would have been minimal, and would have probably never had a problem with the back end.
I was lucky that i learned this lesson in first gear just pulling off from standing, same thing on a motorcycle at speeds could be fatal. Happy and safe ridding, and I hope i'm the only one here that learns that lesson first hand.
