Sealed bearing-gearbox mainshaft highgear?

htown16 · Dec 29, 2015

I ordered a new bearing for the gearbox highgear mainshaft on the primary side from a reputable supplier and received a sealed bearing. The original one is an open type. Concerned about lube reaching the bearing. Something to worry about or not?

Torontonian · Dec 29, 2015

I'd specify open bearing to get oil.

texasSlick · Dec 29, 2015

There was a thread about this issue sometime back. You can do a search to get the general view on this.

My sentiments are open to flush the bearing with oil.

Sealed bearings die of their own wear products captured and contained by the seal.

Open bearings are flushed, and the wear products get into the oil reservoir, where they usually do no damage if the oil is drained at reasonable intervals.

If you agree, you can simply pull the seal.

Slick

Torontonian · Dec 29, 2015

Never considered that, to pull out the seal on say one side , the inboard side obviously.

Danno · Dec 29, 2015

I regularly remove bearing seals, pack the bearings with grease and replace the seals, normally on motorcycle wheel bearings. No reason you couldn't pull the seal and leave it off.

Rohan · Dec 29, 2015

Yes, easy as.

What brand is the bearing ?

Reason for asking is that some of the japanese brands now offer an unconditional 100,000 km warranty on their sealed automotive bearings.
Thats why the auto industry can offer a 3 year warranty....

One of my gearboxs, older dommie, was fiited with such a sealed bearing.
When it reaches a 100,000 km, I'll let you know

Might be a while though...

Torontonian · Dec 29, 2015

New game. 100,000 is a long time.

Davo · Dec 29, 2015

I followed the NOC NSW bearing recommendations. Just removed seal on the inner face of both main shaft bearings. No problems. Google NOC NSW Commando bearings.

baz · Dec 30, 2015

Do not remove the seal the bearing has the right lubricant for its life if you remove it you will introduce oil from the gearbox that could contain contaminates and shorten the bearings life this is what is now done in racing CCMs and the timing side main bearing life has gone from two and a half racing hours to twenty seven racing hours

Rohan · Dec 30, 2015

I would have expected gearbox bearing life to be measured in the thousands of hours regardless,
so 27 (for an engine bearing) doesn't actually sound all that good ?!
Maybe they can't fit something man sized enough for the job in a CCM ?
Superblends, anyone ??

But we diverge...

baz · Dec 30, 2015

Rohan said:
I would have expected gearbox bearing life to be measured in the thousands of hours regardless,
so 27 (for an engine bearing) doesn't actually sound all that good ?!
Maybe they can't fit something man sized enough for the job in a CCM ?
Superblends, anyone ??

But we diverge...

27 racing hours compared to 2 1/2 racing hours sounds good to me this is a direct comparison of a bearing running with or without a bearing seal

Rohan · Dec 30, 2015

It is a good comparison, but that is truly horrid bearing life no matter how you look at it.

Something else is at play here.
I'd be having a word to the engine designer about that....

Harleys have huge heavy flywheels and chunky great pistons, and have near zero bearing problems,
so its only a matter of fitting sufficiently heavy duty parts to do the job ?
BSA Gold Stars don't have near zero life bearings in them either...

But we diverge, muchly....

texasSlick · Dec 30, 2015

baz wrote:

"27 racing hours compared to 2 1/2 racing hours sounds good to me this is a direct comparison of a bearing running with or without a bearing seal"

Could this difference be due to a comparison of a bearing running in grease vs one running in oil? If so, the life of the bearing has nothing to do with wear products either trapped in the race by the seal, or released into the oil reservoir.

Regardless, this is not a good testimonial for oil as a lubricant! How did we ever get bearings to last 100,000 km before seals?

Slick

Rohan · Dec 30, 2015

Something else must be at play here. ? (CCM wise).
Bearings running in oil shouldn't be too far different to running in grease.

The bearings in CCMs must be too heavily loaded, or under specified, or something.
Even the abysmal life of bearings in Combat engines was way better than 27 hours.

Not that this has much to do with bearings in Norton gearboxes.

Some of them must have gone better than 100,000 km.
Didn't the late Gerry Bristow RIP on the NOC do 80,000+ MILES on his Mk3, only routine maintenance.
Don't know what he did about that layshaft bearing though...

baz · Dec 31, 2015

Sorry meant to say bearing in a racing "bsa b44" not CCM they also run sealed bearings on the gearbox output shaft on the racers for improved bearing life

Mark · Dec 31, 2015

well cool, I put a 2RS bearing in my B44.
I just thought that it was a good idea. I didn't know that others did it.

Sealed bearing-gearbox mainshaft highgear?

htown16 · Jan 1, 2016

Decided to pull the inner seal. Popped right out. If open to the gear box has worked in the past, I hope it will continue to.

texasSlick · Jan 1, 2016

htown16 said:
Decided to pull the inner seal. Popped right out. If open to the gear box has worked in the past, I hope it will continue to.

Attaboy!

It takes less torque to turn an open bearing vs sealed ... that equates to less power loss and better fuel economy.

Slick

baz · Jan 3, 2016

Mark said:
well cool, I put a 2RS bearing in my B44.
I just thought that it was a good idea. I didn't know that others did it.

this is exactly how they are raced

baz · Jan 3, 2016

htown16 said:
Decided to pull the inner seal. Popped right out. If open to the gear box has worked in the past, I hope it will continue to.

just out of interest do you know how many miles the bearing you replaced has done ?

Sealed bearing-gearbox mainshaft highgear?

Similar threads