Hole in Chain Case!!??

WFO

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Went to check the oil today and found a loose bolt sticking out of a hole in my chain case! Is this common? Looks like I'll need to replace (or repair) the chain case.
 

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That is the bolt that secures the chaincase cover to the center shaft inside the case. You should be ok by adding some threadlock and tightening. Torque to 7.2 ft/lb or 10 Nm. even with that bolt loose, there is not really any space between the cover and the shaft it bolts into. The only thing I would possibly worry about is there is a washer on the end of the shaft that bolt goes into. Don't think it could work it's way off, but anythings possible. Could have came loose being it wasnt threadlocked when it was put back together? Maybe during last service/repair?

For piece of mind, you can pop the chaincase cover and make sure everything is intact and in place.
 
To me it looks like the bolt that retains the lower gear on the drive shaft and has back right out through the cover.

Time to take it a part and find out what's up. You need to repair that hole in the cover while your at it.

Kaz
 
Kaz said:
To me it looks like the bolt that retains the lower gear on the drive shaft and has back right out through the cover.

Time to take it a part and find out what's up. You need to repair that hole in the cover while your at it.

Kaz

Doooooooooooh, I think you're right, Kaz! The center bolt on the outside is alittle higher. Looks like the lower gear bolt bored a hole right through the cover. Good news is it might not be that bad......as long as nothing inside is damaged. Definitely gotta come apart though. You can propbably patch the chaincase ....or if you're picky and got the $, buy a new one. Lower bolt also has to be threadlocked (to prevent exactly that from happening)
 
NY AttakGT & Kaz........Thanks for your replies. I agree - it looks like the bolt the holds the lower gear onto the drive shaft has worked it way through the chain case cover. The chain case, by the way, was dry.

I don't want to spend the $$ on a new cover, but, obviously, the cover needs to be repaired. How do you suggest fixing the cover?
 
i had this happen to me before. my buddy is a welder by trade and just welded a patch over the hole. good as new tons and tons of miles on the welded cover no problems. if your chaincase was dry you will have to inspect your chain and gears really well for damage and may need to replace them.
 
WFO I happen to have a brand new updated chaincase cover, I bought it to update the 06 cover because they leaked and when I pulled mine apart it was already updated by the previous owner. You can have it for $140 I paid $155 plus shipping.

When is the last time that unit was serviced? You may have a lot more wrong in there hopefully not though!
 
I had this same thing happen on my old Indy Trail. I caught it before the bolt head cut a hole all the way through the cover.

I had the cover off and saw the wear mark. It was seriously paper thin and almost popped through. Clean bolt and the shaft threads, apply locktite and torque to spec.
 
Is this somethng that could be common to all Yamaha sleds?

Still haven't gotten around to tearing into mine yet but hope to soon! :o|
 
Don't bother inspecting the chain, don't even think about it, REPLACE IT. Inspect everything else in the chaincase, gears are 99.9% fine, be worried about the BEARINGS. If they're still smooth and tight, you may leave them, any roughness or looseness, replace.
 
BTW: Where did the oil go? I don't see any kind of oil mess in there like you should expect from something like this.
 
Irv said:
Is this somethng that could be common to all Yamaha sleds?

Still haven't gotten around to tearing into mine yet but hope to soon! :o|

This can happen to any sled from any brand if there is a bolt and washer holding the upper or lower gear on there respective shaft just inside the chaincase cover. The problem is usually when they are taken apart and then put back together without clean threads or lock-tite.
 
Loctite is your friend. This is why you sbould pull the case apart mid season, you'll find suprises like these before they becomes major problems. This is also why the guys thinking that if the bolt breaks (mostly a Nytro issue) it's no big deal.
 
Snowmobileaddict said:
Irv said:
Is this somethng that could be common to all Yamaha sleds?

Still haven't gotten around to tearing into mine yet but hope to soon! :o|

This can happen to any sled from any brand if there is a bolt and washer holding the upper or lower gear on there respective shaft just inside the chaincase cover. The problem is usually when they are taken apart and then put back together without clean threads or lock-tite.

Thanks, good to know ;)!
 


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