Upper gear (drive sprocket assembly) bushing wear, End of season maintainance...

[Pstn head]

My lower panel is off right now, so glad l read this! I just ordered the rivet nut set and gun. What size did you use?

I used an m6 button head torx style bolts and flat washer, both are non corroding type fasteners with aluminum rivet nuts. I can't remember the drill bit size but just size it up against your rivet nut and a test hole in some other material. Just leave out the one by the upper shock mount, lots of material there and not really needed. I might go smaller next time, m6 is a little overkill.

 

[hellflyer]

Sounds good! I ordered the steel ones in a kit, m4 to m8 I think. I might try the m5 and use the Yamaha panel bolts with the shoulder and large Philips head. I have a few kicking around.

 

[snowbeast]

I was made aware of this issue becouse of your thread a couple of years ago in the Viper section. That's why this site
Is Number-1, members on this site are so knowledgeable, helpful and informative, like yourself and others.

It's to bad really that it couldn't be a splined gear somehow (maybe a diffrent reverse setup) or something so it doesn't wear and maybe be catastrophic if not attended to.
Looks like this will be a mid season thing to do from now on.

Is your sled stock hp,? Reason I ask,is mine is not,and the chaincase is the weak link to this skids set up for sure. Now I wonder how long it will stay togeather at 270 hp.

 

[Pstn head]

Is your sled stock hp,? Reason I ask,is mine is not,and the chaincase is the weak link to this skids set up for sure. Now I wonder how long it will stay togeather at 270 hp.

Yes stock hp.

 

[yamaha06]

Do you happen to have the part # for the gear? I changed mine out on the viper every year just to make sure I never had any issues, I probably should do the same for the sidewinder.
Thanks

 

[Yamadog]

Is your sled stock hp,? Reason I ask,is mine is not,and the chaincase is the weak link to this skids set up for sure. Now I wonder how long it will stay togeather at 270 hp.

Well my vipers are at 265 go and ran stick gears and chains for 3 years before upgrading and no problems with that stuff just motors and head gaskets. I am still running the original single ply 1.6" camoplast with 144 studs and it looks like new with over 6000 miles on it. I have destroyed limiter straps, tried hub and wear bars but the basic sled is bullet proof.

 

[Pstn head]

Do you happen to have the part # for the gear? I changed mine out on the viper every year just to make sure I never had any issues, I probably should do the same for the sidewinder.
Thanks

Here's the part # 8KC-E769A-10 drive sprocket #*$&@. IMO it's cheap maintainance, if done when you change the oil and the oil tank is empty, plus you get a visual of the inside of the chaincase if anything needs attention and cleaning.

 

[yamaha06]

How did your bottom gear look on yours (the 40t)? I'm installing a new top gear but the bottom gear feels really rough feeling around the edge of the teeth, but it almost looks like it was made this way, doesn't seem normal though.

 

[Pstn head]

How did your bottom gear look on yours? I'm installing a new top gear but the bottom gear feels really rough feeling around the edge of the teeth, but it almost looks like it was made this way, doesn't seem normal though.

All my other gears seemed fine, even the top gear (the teeth) seemed good, it was the coating on the surface where it contacts on the upper shaft that was worn, pretty much all gone. The first pic is the old gear. Notice the coating missing compared to the new gear.

 

[yamaha06]

View attachment 129351 View attachment 129352
All my other gears seemed fine, even the top gear (the teeth) seemed good, it was the coating on the surface where it contacts on the upper shaft that was worn, pretty much all gone. The first pic is the old gear. Notice the coating missing compared to the new gear.

Ya mines the same way, so I'm changing it out. I was just curious about the bottom gear. It looks fine but when you rub your finger along the outside of the teeth on the face it feels rough and not smooth like the other gears. It's almost looks like casting marks on the gear.

 

[yamaha06]

When you look at this picture and look at the top of the teeth you can see the burrs, they should be smooth.

 

[Pstn head]

Ya mines the same way, so I'm changing it out. I was just curious about the bottom gear. It looks fine but when you rub your finger along the outside of the teeth on the face it feels rough and not smooth like the other gears. It's almost looks like casting marks on the gear.

IMO if your not happy with how your bottom gear feels, change it out for peace of mind, probably it's fine but for what it's worth, I would change it out. I also replaced both my chains, the forward drive chain had zero adjustment, if the chain would have stretched anymore than it was already. Also have a look at the plastic guides, especially the forward chain guide, mine had groves in it from the chain.

 

[Pstn head]

When you look at this picture and look at the top of the teeth you can see the burrs, they should be smooth.

It's hard for me to tell from the picture but I don't bielieve it's too expensive and since your there I'd change it out, only for piece of mind.
I pretty much replaced all my chaincase internals, since I was in there. IMO these top gears need replacing more often than not depending on how many km's per season.

 

[fatchance]

Replaced my top gear with 2085 miles on it. The new gear measured a half a mil tighter than the worn gear. I'm glad i went back in there to change this out after getting some good advice!