Lower gear bolt

[ViperTurboPete]

I was at the Yamaha dealer the other day picking mechanic buddy's brain on the Nytro. He said there is an update for the 2010 for the bolt that holds the bottom gear. I guess it is a little longer and the 08/09 Nytro's have experienced the bolt coming out and doing some damage. I read the update on it.

Anyway, I bought the new bolt for a few bucks and thought I would pass it on.

 

[tapex_07]

I thought the bolt was being cut shorter by others, not longer????

 

[ViperTurboPete]

Whatever it is...shorter or longer. I haven't taken mine out yet. All I know that it is an update for 2010 and was just throwing it out there.

 

[bradthebest]

mine broke , i talked to my dealer today about it . they hadn't herd about it but they are going to talk to a rep .

i was surprised they hadn't herd of it . our mechanic is rated as the second best yamaha mechanic in canada . he searched through a tonne of bulletins looking for something but nothing came up .

hopefully the yamaha rep is aware of it .

 

[akvector]

mine was broken and laying in the case. My dealer knew knothing about it being a problem either and they did not stock the bolt. so i went to the local hardware store and procured a bolt.

it is not what i wanted but it is working well so far.

 

[YamaMTX]

akvector I did the same thing!

 

[ViperTurboPete]

The Yamaha mechanic guy I deal with is very reputable. He was telling me about how the bolts are breaking and read me the bolt update for 2010.

 

[bradthebest]

talked to the dealer today , they are ordering me the updated bolt .

supposedly most non-turbo guys just don't run the bolt , same with the turbo'd ones . some are having the bearing fail prematurely and wrecking covers .

or at least that was what i was told .

 

[swelly]

mine was broken and laying in the case. My dealer knew knothing about it being a problem either and they did not stock the bolt. so i went to the local hardware store and procured a bolt.

it is not what i wanted but it is working well so far.[/quote

Surprised your dealer did not know about. This came about a long time ago, and the dealer I go to here in Anchorage knew all about it. At least in the Service dept. Service mgr is riding a boosted sled and his broke, kept on riding for the rest of last season, so that convinced me. Told me no worries it just hold stuff together for assembly. If it breaks, it either drobs to the bottom or just floats against the cover till taken apart.

Mine has never broke, but I do think, be gentle when putting in Reverse. This comes from the old days when I used to work at a Polaris dealer, b4 I seen the light. lol

Now I fix tractors painted orange, and manage the parts dept. Neat thing is they hardly ever break.

 

[bradthebest]

mine was broken and laying in the case. My dealer knew knothing about it being a problem either and they did not stock the bolt. so i went to the local hardware store and procured a bolt.

it is not what i wanted but it is working well so far.[/quote

Surprised your dealer did not know about. This came about a long time ago, and the dealer I go to here in Anchorage knew all about it. At least in the Service dept. Service mgr is riding a boosted sled and his broke, kept on riding for the rest of last season, so that convinced me. Told me no worries it just hold stuff together for assembly. If it breaks, it either drobs to the bottom or just floats against the cover till taken apart.

Mine has never broke, but I do think, be gentle when putting in Reverse. This comes from the old days when I used to work at a Polaris dealer, b4 I seen the light. lol

Now I fix tractors painted orange, and manage the parts dept. Neat thing is they hardly ever break.

the mechanic at our shop told me some of the guys running boosted nytro's with the bolt missing were blowing cases .

when i installed mine i could hear the shaft moving back to center as i tightened the bolt .

that was enough for me to be a strong believer in having it there .

Yamaha wouldn't put it there if there wasn't a reason , and that reason isn't so it is easier to work on i can guarantee that .

i was also told that it is more of a problem on mountain machines , most likely from guys jamming it in reverse when they are stuck .

if mine breaks again i will drill it slightly larger , i have a grade 12.9 1.00 tpi bolt that will replace that weird thread yamaha is using .

i personally cant find a m10 in 1.25 that is anything better then 8.8 . i have a mit full of 12.9's in m10 , m11 and m12 all fine thread . long story short , if it breaks again i will fix it for real .

 

[scmurs]

I had my 2010 apart to install a 2.5" CE. There is a snap ring inside of the counter-bore that, if the lower bolt breaks, will prevent the broken part of the bolt from getting out of the counter-bore and bouncing around against the chaincase. The outer hub on the lower gear has a groove machined inside of it where the snap ring engages. Not sure if that lower hub on the 08-09 models will accept that snap ring or not.

scmurs

 

[Tobbe...]

mine was broken and laying in the case. My dealer knew knothing about it being a problem either and they did not stock the bolt. so i went to the local hardware store and procured a bolt.

it is not what i wanted but it is working well so far.

I have now learned that this is abolutely normal when you address a problem to a Yamaha dealer-at least here in Sweden.
The dealer i used previusly -got myself a new one now, its three hours of driving instead if 20 minutes, but its worth it...- had never heard of bad handwarmers, loose bolts in the front suspention-yes, mine got loose but in very slow speed so nothing happend, and broken bolts-"how are you driving?" they asked me...

I´m starting to wonder if Yamaha never inform their dealers of common issues? My new dealer -witch so far has been fantastic btw- told me that last wear they sold 38 Nytro RTX/XTX/MTX and of thiese they have so far changed the lower bolt in 22 of them-they are allowed to change it on sleds that the bolt is allready broken, but not to do it before it break since it rearely make any damage. Way to go Yamaha...

Other than that i am very pleased with the sled so far, so pleast that i picked up a new identical Nytro that i had last year-in 20 years with Cat it has never happened before!

 

[ViperTurboPete]

I tore open my chain case the other day. The lower bolt was broken off. There was no sign of the bolt head. I guess it may have been chewed up by the chain. I used an easy out to get the bolt out of the shaft and replaced it with the new one. There was no damage inside so I was lucky.

Good thing the dealer mechanic gave me the heads up!

 

[murph]

Chain didn't chew up the bolt....

When head breaks off, it stays inside the recess in the chaincase cover, inside the bearing that is pressed in the cover.

 

[ViperTurboPete]

You are probably right! Well, more than probably. I hope that is not a problem with that still in there. I don't want to tear down again.