Broken Bottom Gear Chaincase Bolt

[minks_698]

Anybody ever break the bolt holding the lower gear(s) in the chaincase?
Noticed mine was sheared flush with the end of the drive-axle when re-assembling the other day.
The spring for the reverse gear holds everything in place, so I put it together and kept riding, doesn't seem like it could go anywere.
Not sure how it broke in the first place, will it cause probs in the future?

 

[YamaMTX]

This has been covered alot in the past. Almost everyone that has had a nytro with reverse apart has a broken bolt. No one has come up with an explanation or a perminent fix. Most are riding it the way it is with no problems.

 

[Alatalo]

No one has come up with an explanation or a perminent fix.

The fix is the -09 drive axle and bolt (different thread length).

 

[YamaMTX]

I have a 2009 Nytro and it was still broke! Is there another fix I am missing? I have read many threads on it and never found any solid solution. They say there was a upgraded bolt but heard those broke the same way.

 

[Snoxracer242]

Same here, I ended up getting a Hardened bolt from a local hardware store and it hasn't broke yet. Not sure what would cause the bolt to break, but the bearing in the outside cover should hold everything in place, tell the broken bolt wads up next to the chain case.

 

[yamahaboy701]

Mine was broke too. I am putting the 2010 version in. Lets see.... 2010 subframe.... 2010 ball joints.... 2010 chaincase bolt. Let hope they got it right this year otherwise hello 2011.

I used a easy out but it came out so easy you could just use a screw driver maybe?

 

[DeerHuntr]

Is ther any symptoms of this?? I changed my chaincase lube but never pulled the cover, has me a little concearned. 1400 miles on my 09

 

[arteeex]

No symptoms. From what I can tell the bolt is there to aid assembly. I don't see what's loading the bolt to cause this failure. But I suspect it's because the drive shaft is restrained on both ends from axial movement, so something has to give when the shaft flexes.

As noted, the broken section will come out easily. I drilled an 1/8" hole and tapped a square-drive screwdriver bit in, then backed the section out.

 

[EsonPZ]

Mine was broken too. Yamaha changed the bolt for the 09 models and for -10 they have a new drive axle and new bolt again.

 

[Alatalo]

Strange...
I was under the impression that the update for -09 fixed the problem.
I have had my -09 chaincase apart couple of times and I never found a broken bolt.
Are you sure you are using the correct 55 Nm torque spec...?

 

[RealDeal]

Mine was broke to, for how long who knows. I used the same method as yamahaboy to fix it. Mine is a 2008.

 

[gunner2]

Mine was broken too 09 se so the 09 are not any better...

 

[Zakre]

which bolt is it exactly, any pics, i think i should be checking mine then??? 09 xtx 1100 miles

 

[BooBoo]

Mine broke on my 08. I put in the up dated bolt and used the right torque spec and haven't had no problems to date

 

[LJ 452]

See pic.