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[jfw]

What started as exploration to see if I could sort the gear box oil seeping out via the kickstarter shaft has lead to the main shaft bearing. When I drained the oil it was a rusty brown and as soon as I got the cover of things I could see why. The bearing on timing side is a sealed bearing with a metal seal. That metal seal was all rusted. I pulled the cover and pulled the bearing to find both side's seals rusty and the bearing very rough. So obviously replacement is in order and thankfully our host's replacement has rubber seal, instead of metal, so no possibility of them rusting.


My question is about lubrication and maintenance of the bearing. I sort of had an idea that if I pulled the seal from the inner side of the bearing it would get splashed with gear box oil. That might be the maddest idea ever but the state of the old bearing is so rough it feels like there was no lubrication in there at all. Maybe you're supposed to repack grease into them every so often, in which case I am at fault. So what's the correct procedure? I'd love to hear your opinions.


So before I fit the new rubber sealed main shaft bearing tomorrow is there anything I should be taking care to do? Thanks for reading.

[Gwilly]

There will be one or two that disagree but its for this very reason that i always remove the inner seal on gearbox bearings and allow the oil to splash lube..

I don't expect to be replacing gearbox bearings until at least 50,000 miles when they get thrown away as part of an inspection/refurb..

Besides how do you grease the output bearing behind the drive sprocket on a regular basis? Has to be self lubricating from within.

Not your fault its rusted up..... Not guilty m'lud.

[John R]

Now, I have recently refitted all the gearbox bearings on my '89 Bullet at about 70,000 miles. The thing that prompted me to do it was the demise of the drive side layshaft bush, which turned out to have worn right through to the casing.
I replaced the mainshaft bearings, which had been open bearings, with sealed ones and despite a lot of controversy on this board, I left the seals in place. My reasoning for this is that we trust these bearings in our cars and modern bikes. They are dirt proof (unless they rust!) and are sold for their application by Hitchcock's who have massive experience with Bullets.

[jfw]

I can imagine there'll be a lot of contrary opinion, and maybe there's a great reason not to do this, but in my head it makes sense to strip the inner seal. Having said that I'm here because I have no scientific basis or data on which to base my logic. If I knew it all I'd be else where



Thanks a million for your thoughts on the subject. I'll check in here in the morning and see what the consensus is.

[Tim NZ]

It is rare for the Kstart O ring to not seal. The most common reason for the 'kick start' to leak is actually from oil being ejected from out of the mainshaft bearing retaining cap. It runs down over the Kstart but is not easy to see.


The lubricant in the gear-box is passing the slingers.


I vent the gear-box by drilling a wee hole up into, and then across out of the Oil filler plug.


That allows the 'box to breath and usually fixes it. (The early Redditch box's had a vent hole drilled, high up, through the inner cover)


Post 2002 the gear box design was improved to stop the oil leaks at the sprocket. So depending on the year of your gearbox, apply some low strength sealant between the sleeve and the inner race to prevent oil migrating out under the bearing and along the splines and past the sprocket.

[Dennis C]

SFL bearings, sealed for life, as John says all modern cars bikes etcetera use them sealed why change them.

[PeteF]

Are we talking about the Albion box here?

If so then they come with non sealed bearings and are filled with 00 grease as standard. People fit sealed bearings so they can use oil in the box without it leaking out (though I can't see what's wrong with the grease myself)
Removing the inner seal is quite usual on many applications and would work here. On the other hand, it doesn't get a particularly hard life so it would be fine as SFL as Dennis says.
The thing is to buy a quality bearing.
The kickstart shaft only has an O ring to seal it and doesn't generally leak using grease. If you have oil in there it would be more prone to.

[Nettshubby]

Yes, it would help to know which bike/ gearbox you have. And the manual for the 4 speed indian bikes advises topping up the grease with 90 gear oil, or was it 20-50? Occasionally.

[PeteF]

20/50 Nettshubby. I think they say that as the grease is a bugger to get in.
I find a dollop of black Moly in with the grease helps the gearchange.

[jfw]

Thanks for all your thoughts. I left the bearings as it was, sealed. Once I'd fitted the sealed bearing my brother said that I should have pulled a seal off one side and really packed it with grease before resealing it. He's an agriculturist and says that even the European bearings come with very little, cheap, light grease which just vanishes when bearing gets warm. I'd already fitted the bearing so it's staying the way it came.


Sorry I should have said when I started this, 2003 Indian Bullet 500 kickstart model.