Constant small oil leak - time for transmission vent?

GKRyder

Joined
Mar 20, 2016
Messages
171
I'm not sure what this is?

End of a shaft , oil galley?

Constant small oil leak - time for transmission vent?


Always a bit weapy.

Looked at Richard's manual for clutch so seams to sit below clutch basket.

Thanks for any assistance.
 
Take off countershaft cover and see if its coming from the seal behind the front sprocket. If so , check the chain tension , don't have it too tight as this can cause shaft and seal flex/distortion. Install the trans vent if you don't have one. I am surprised that you still don't have the trans vent after all this time on this site.
 
Thanks Tony.
Will do.

Apologies at my seemingly laxed attention.

I won't confuse time on site with time I had the bike back with me , a total of 4 months. :(
 
Hello GKRyder , Let us know how it goes . Hopefully this will solve it.
 
OK so...

I checked the chain. Good 35mm slack.
Rubber seal looks in good condition and well fitted as well.

Changed the oil in transmission (as was suspicious full synth was put in at last dealer engagement) to semi synth - this fixed my graunching/juddering clutch on take up by the way.

Still a small leak.

Will fit trans vent but beyond that don't know what else to try?
Perhaps sprocket is on too tight, could that do anything there?

Regards.
 
I don't think it would be too tight, but try the trans vent first of course . I have read the UK NOC forums and leaking countershaft seals have been repaired by Norton in the past. Will you be doing the work ? If so there may be 3 parts to look at buying. Find on the drawing of the transmission gear set Items 51 , 52 and 53. 51 - seal ring , 52 seal case , and 53 o-ring . All of these parts can be replaced after the countershaft sprocket is removed. Can you see the oil coming from the countershaft seal area ? Does it leak only after its been ridden ? Try the Trans Vent first..
 
I can see it ever so slightly 'wet' around seal.
Good question about if after riding will check.

Vent is going on regardless.
 
Just had my output shaft seal replaced under warranty for the second time, after the first replacement it still leaked (gearbox was overfilled so that would not have helped) fitted a vent but still leaked so took it to the new Norton dealer in Austin and they replaced seals. Just done over 200 miles and it's fine. A vent is the way to go.
 
After conversations with Richard about my particularly noisy clutch and possibility he through out there is that the shaft might be bent.

I'm guessing this would put stress there as well.

And if the bearings are cactus as well now then could explain why so rattly (metal on metal type sound) under load.

Trans vent makes sense in any case I know but I will need the dealer to check things while final months of warranty.
 
Just to be clear, not a bent shaft. The shaft that the clutch basket rides on could be worn. Causing that sound. If the spacing is wrong on the basket for the bearings, it causes the inner race to jam which can cause a bearing to spin the inner race on the shaft. This defeats the purpose of the bearing and wears the shaft to a point, even the new basket wont work properly. Hence you could need a new shaft and a new basket. I'm
Talking a few thousands of an inch is all it takes. It happened to my dads bike too. New shaft and basket fixed it. These are hand built bikes. Not perfect in every way. I guess part of the uniqueness is low volumes. Which means less people ride them as daily which means it takes longer for these problems to show up.
 
Sorry to misquote you Richard.
Re-read the replies, big difference...yes potentially worn not bent.

Starting to make sense.

Find out soon I guess.
 
The leak or more correctly seepage in the area in the pic has been documented years ago on this forum. It happens on new bikes so its not wear. Most people reported not enough seepage to show a drip mark on the garage floor so I suspect this commonly goes un-diagnosed!
 
What this requires is a proper British fix.

It must be done thoroughly:

Wipe off seapage,

Carry on!
 
Fast Eddie said:
What this requires is a proper British fix.

It must be done thoroughly:

Wipe off seapage]


If I remember correctly this is caused by a burr or small lip on the case causing the seal to not seat 100% It should not get worse with mileage. And as Eddie said a couple of guys just elected to give it a quick wipe when giving the bike an after ride cleaning and inspection!
Click to expand...
 
Several of the other owners had the vent prior to discovering this issue, hence my statement that the vent won't help this seepage!
 
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