Chaincase Bearings

How do you run your chaincase bearing seals?

  • No seals, both removed.

    Votes: 1 4.0%

  • Fully sealed, seals both sides.

    Votes: 7 28.0%

  • Seal on oil side, open on back.

    Votes: 6 24.0%

  • Seal on back, open to chaincase lube.

    Votes: 11 44.0%
  • Total voters
    25
make sure you spin the bearing as thats how its drawn in. And i am sure youd know this but the bearing would need to be dry and not grease filled to perform the test, as the grease would need to be heated up to lower its viscosity to move around some, so if you clean the bearing with carb cleaner or something like that and then replace the seal, and spin it, it will be dry and noisy, now put on your gear lube and continue spinning, youll find the results to be a little upsetting for you. Be sure to ask your bearing counter worker on this too, I am sure you will recieve the correct answer.....cough,cough.

I used to work for a bearing distributor, thats doesnt go very far in anyones book, they hire counter workers where you pick up your parts, not engineers.....lol


Like I said, rip all the seals out of your sled and run it if it makes you happy.

and again for the airlock theory, the gap is about 2-3mm, between the bearing and seal face, "big airlock to have"........sorry, thats just a crock.....

I didnt need to ask a yamaha engineer about the seepage, I see it everytime I change a track, as if the sled has some miles on it, it usually needs a seal on the shaft too from dirt, sand,debris and crud being in the recess where it sits. I would just be guessing here, but I might, just might, have changed 1 more then you??? nah..... probally not
 
mrviper700 said:
make sure you spin the bearing as thats how its drawn in. And i am sure youd know this but the bearing would need to be dry and not grease filled to perform the test, as the grease would need to be heated up to lower its viscosity to move around some, so if you clean the bearing with carb cleaner or something like that and then replace the seal, and spin it, it will be dry and noisy, now put on your gear lube and continue spinning, youll find the results to be a little upsetting for you. Be sure to ask your bearing counter worker on this too, I am sure you will recieve the correct answer.....cough,cough.

I used to work for a bearing distributor, thats doesnt go very far in anyones book, they hire counter workers where you pick up your parts, not engineers.....lol


Like I said, rip all the seals out of your sled and run it if it makes you happy.

and again for the airlock theory, the gap is about 2-3mm, between the bearing and seal face, "big airlock to have"........sorry, thats just a crock.....

I didnt need to ask a yamaha engineer about the seepage, I see it everytime I change a track, as if the sled has some miles on it, it usually needs a seal on the shaft too from dirt, sand,debris and crud being in the recess where it sits. I would just be guessing here, but I might, just might, have changed 1 more then you??? nah..... probally not
Click to expand...


I was looking for information and dared to question a theory.....which may even be correct.....I do have an open mind about these things.

It might be worth going back and reading what I originally posted, "I could be wrong and will stand corrected if I am but I really can't see oil being drawn through the seal or past the splines being counted on for lubrication". The key words here are counted on.

Unfortunately you have trouble responding in a mature manner and that just kills your credibility as far as I am concerned.

In any event the pole result is interesting, the majority are leaving their bearings open to the oil.

Ride Safe.
 
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for what it's worth I'll post my observations.....

I religiously change my driveline bearings every two seasons on both sleds.... every time I have disassembled and removed the chaincase there was clear coloured gear lube between the case bearings and the shaft seals for both drive and jack shafts... both bearings were saturated with lube to the point where is was leaking out...

these bearing all have the seals removed on the tunnel side and not removed on the case oil side...

I too thought it was odd removing only that seal but now totally convinced the lube does wick past the splines/shaft to the other side.... it doesn't matter how often I change case oil, it always seems black and gritty when I do drain it.... That contaminated oil is not something I want in those bearings...

Yamaha has good reasons for doing things this way and the first that comes to mind is 9 out of 10 sled owners likely won't change the case oil twice in the sleds life time and if the driveline bearings were to be open in such a dirty environment they surely would fail... my guess is there were a lot of bearing failures years ago for this reason....

just my two cents..

tj
 
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I had a 87 Exciter with 11500Km on it and only changed the bearing when I changed the track (at 10,000Km and only becase it was all apart). The chain case bearings were open to the chain lube. Changing the oil was a bit of a pain because there was no drain plug.

With the newer machines Yamaha was smart enough to engineer a drain plug into the chain case which makes draining the oil out a breeze. In fact chainging the oil in your chain case is easier then chainging the oil in your car. Why anyone wouldn't do each year before the season starts is questionable to me. It'll cost you less than $10.00 Canadian!!! How often do you guys change the oil in your car????

I am an engineer (albeit electrical), and the clutch side bearings on ALL of my sleds have never lasted as long as the ones in the oil bath of the chaincase. I also don't believe that the bearing seal & splines etc. would act as that great a filter to keep contaminants out of the bearing. The magnetic dip stick does a good job of keeping the larger particles out of the way.

When I get fed up with IT computer world, I think I might want to drive a milk truck!! Some of the nicest people I've met were truck drivers.

Cheers,

Exciterfan
 
I believe Yamaha has thought this through and I have no reason to alter seal arrangements on my sleds....

Since I am changing bearings every two years my probabilty of experiencing a failed bearing is reduced significantly...

With strict maintainence procedures, it likely doesn't matter where the seals are or are not.... I simply prefer to seal the case oil side,, just as Yamaha did from the factory...



I wish I could drink milk...

tj
 
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My family has drove a milk truck for 105 years. Started with a team of horse and a wagon. Payment every two weeks and a load every day, rain, mud, snow, the milk truck rolls and the money comes in. :WayCool:
 
why people are not just following yamaha engineers is thier choice, each person can take the info and do what they want. I found that putting the bearing back on the way it was recommended stopped bigger pieces of contanments from getting in the bearing because of the seal and kept out the bigger pieces that the magnetic dip stick didnt pickup. the bearing had plenty of lube and the seal was nice and wet. changing your oil doenst mean your bearing will stay good, it helps more than anything else but you could change your oil today and get a piece of metal flake in there right after. the seal will increase your odds of the bearing making until the next change, no seal and that will get in your bearing and possibly make it fail. again different ways of looking at it,
 
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