Shielded Mainshaft Bearing

olympus · Jul 14, 2018

Hi Gents
Gearbox Main shaft (inner) bearing supplied by RGM has shielding on both sides. your wealth of wisdom please
Remove the inner shield or leave insitu

kommando · Jul 14, 2018

Remove inner shield.

L.A.B. · Jul 14, 2018

olympus said:
Gearbox Main shaft (inner) bearing

The 'timing side' (RLS 9) bearing?

I'd remove both as the clutch lifter mechanism relies on oil passing through the bearing for lubrication.

olympus · Jul 15, 2018

Drive side bearing... not timing

L.A.B. · Jul 15, 2018

olympus said:
Drive side bearing... not timing

The sleeve gear bearing.

https://andover-norton.co.uk/en/shop-details/18011

Yes, at least remove the inner shield.

baz · Jul 15, 2018

We have been down this road before ,personally I would leave the shields on the bearing
The bearing is sealed and lubed for its designed life span I really do doubt it would last longer with oil from a Norton gearbox entered into it

L.A.B. · Jul 15, 2018

baz said:
We have been down this road before ,personally I would leave the shields on the bearing
The bearing is sealed and lubed for its designed life span I really do doubt it would last longer with oil from a Norton gearbox entered into it

Shielded bearings are not "sealed" bearings therefore any lube inside the shielded bearing would eventually be diluted and washed away by gearbox oil.

https://www.bearingworks.com/technical-data/seals-and-shields.php

‘Z’ Type Shield – The ‘Z’ type shield is a metal shield that typically is non-removable after installation as is it pressed in. There is a small gap about .005 inches between the shield and inner race. There is no contact so obtainable speeds and torque are not effected as in a contact type seal. Lubricant leakage can occur and contamination can enter through this gap. They have fair dust resistance and poor water resistance. Shields are good to around 350 F.

baz · Jul 15, 2018

Yes I agree a shielded bearing isn't sealed but I can't see the gearbox oil washing away the grease and not putting anything back
This is what I have done on my norton gearbox and also on the timing side main bearing of my BSA b44

L.A.B. · Jul 16, 2018

baz said:
Yes I agree a shielded bearing isn't sealed but I can't see the gearbox oil washing away the grease and not putting anything back

Sorry, but I don't follow? If you agree gearbox oil can get into the bearing and wash the grease out it will then be lubricated by gearbox oil, same as if the shield wasn't there.

baz · Jul 16, 2018

I'd like to think that the shield would keep out the larger debris that are present in the Norton gearbox
The next time I take my gearbox apart I will break the shield out and see if there is any grease left ,or if it's bone dry or full of oil

pommie john · Jul 16, 2018

Just to be clear, is it a rubber seal or a metal shield?

L.A.B. · Jul 16, 2018

baz said:
I'd like to think that the shield would keep out the larger debris that are present in the Norton gearbox

The sleeve gear bearing is already shielded against debris by the sleeve (4th) gear pinion.
https://www.oldbritts.com/gearbox_a.html

http://www.doov.com/apps/nortoncomp...t&view=article&id=25:layshaft-bearing-upgrade

baz · Jul 16, 2018

All I can say is it works for me

Shielded Mainshaft Bearing

olympus

kommando

L.A.B.

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olympus

L.A.B.

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baz

L.A.B.

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pommie john

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