Chain case counter gear...is this normal?

[Long Track]

Took apart my chain case last night to change the drive shaft and found the counter gear with heavy impressions of the chain on it. Is this normal? Can I reuse the gear? Should I be considering changing the chain too? The bottom gear has a light impression no where near this one. Tks

 

[black knight]

When i had mine apart this summer i remember similar marks. Didn't look at the gear as close as you did though.
My chain spec. was well within the limit from the manual. I left everything as is. Haven't heard much of anything on hear about gears and chains being trouble. I've got 10,000km on mine.

 

[SIMMER]

Never seen that before. Mine was fine. How many miles?

 

[Handy]

Looking at that gear the wear looks like an oil problem. You shouldn't have that scuffing on the sides of the teeth if the oil is doing its job.

 

[kinger]

That is severely damaged you have a oil problem, there should be no wear on the gears period. I have seen gears from 1000 miles to 10,000 miles between all the yamaha sleds I have tore apart and you cant tell them from new.

What oil are you running?

 

[Long Track]

I run Amsoil 100% synthetic chain case oil since day one. I thought the same thing but my buddy uses the same oil I do and his doesn't look like this and we both have the same mileage. Not to mention that I change my oil at least 3 times a season to prevent this kind of stuff from happening.

On a side note I just got back from the local Yamaha dealer and they said that this is perfectly normal...Ah I don't think so!!

 

[kinger]

You change the chain case oil 3 times a year? I use everything from ATF to Royal purple gear lube 75w90 and never any damage like that. How do you set your chain tension? Common practice is finger tight back off 1/4 turn.

 

[Long Track]

Yes it's cheap insurance in my opinion. I set the tension as you described always have. Maybe I have a bad batch of gears where the metal is too soft.

 

[kinger]

Doesn't look cheap to me ha ha... just kidding

Bad batch of gears is a stretch, I would throw in a new or used one (yamaha OEM though no aftermarket) and monitor it for next year. Really you only need to change the fluid one a year. I woudl stop with the amsoil and just go to a 75w90 like the manual says with a GL rating that meets spec (cant remember off the top of my head).

Or if you want to be a mythbuster, get another gear keep the amsoil see if it happens again, if not boom bad gear OR if it does happen again get ANOTHER gear use a 75W90 and see if it happens again if not then boom amsoil chain case is not compatiable with yamaha gears.

Good luck and back to yuor original question on running it I would not run that gear IMO especially since the top gears are fairly cheap the bottom with reverse are spendy.

 

[Budweiser]

Could the scratch marks on the side be from where the reverse is not engaging? The grinding noise some people (including me) hear? Mine grinds periodically when engaging reverse, usually when there is pressure on track. I changed all drive bearings this spring and noticed that exact scuffing on on the gear that the reverse engages with. I don't remember which gear it is, big or small. I don't remember any damage to the teeth like you have though.

 

[Long Track]

Doesn't look cheap to me ha ha... just kidding

Bad batch of gears is a stretch, I would throw in a new or used one (yamaha OEM though no aftermarket) and monitor it for next year. Really you only need to change the fluid one a year. I woudl stop with the amsoil and just go to a 75w90 like the manual says with a GL rating that meets spec (cant remember off the top of my head).

Or if you want to be a mythbuster, get another gear keep the amsoil see if it happens again, if not boom bad gear OR if it does happen again get ANOTHER gear use a 75W90 and see if it happens again if not then boom amsoil chain case is not compatiable with yamaha gears.

Good luck and back to yuor original question on running it I would not run that gear IMO especially since the top gears are fairly cheap the bottom with reverse are spendy.

Thanks Kinger - Do you think I should change the chain, it appears perfectly normal but I'm worried that there may be damage that cannot be detected by the eyes.

 

[Viper_Dave]

I work with chain drives every day in my job. If you change the gear, change the chain. I would NOT run the gear/chain combo if I saw those marks. Look closely at the pin rollers on your chain. I'd wager they, and the plates on the inside of your chain, will show significant wear

 

[Long Track]

I work with chain drives every day in my job. If you change the gear, change the chain. I would NOT run the gear/chain combo if I saw those marks. Look closely at the pin rollers on your chain. I'd wager they, and the plates on the inside of your chain, will show significant wear

Thanks I thought so. I'm pretty bummed about the whole thing...now I need to spend an extra $250 bills I didn't plan for. I guess it's better than spending it on a tow truck.

 

[downlow]

Nice..

Looks like chain may be too tight. Look at that gear, wow Yamaha sure is getting cheap, that gear has a terrible surface finish. Its probable these are too soft as mine looked like that slightly. Bet they had teeth breaking off so they reduced harness or case depth.
I understand form and function but for what these sleds cost they better watch quality else lose buyers.

 

[copo427ss]

my reverse gear has the same marks, just not as deep. im running amsoil severe gear marine lube. the rest of my gears look fine. just my reverse gear. no its not from grinding gears in reverse. thats a different set. save yourself some money and order a "team" hyvo chain. it IS a borg warner chain made in canada. same as yamaha. just cheaper $$. i would replace your gear though as a new chain wont have the wear marks matching the gear and will cause premature wear on the chain. at least you didnt blow the chaincase apart.