Fitting Main Shaft Oil Seal to Comet

Martyn Goodwin

Well Known and Active Forum User
Non-VOC Member
Slowly working towards a reliable and civilized daily ride Iam now turning my attention to the oil level in the chain case on my Comet. Once set to the correct level – as indicated by the “level” drain screw I find that after a brisk 200 mile run I start to experience mild clutch sticking (a Honda clutch is already installed) and copious oil on the rearwheel. At that point I can then drain almost a full cup of excess oil out of the chain case thru the “level” screw hole on the chain case cover. I figure once the oil level in the chain case rises above the designed level it then gets onto the rear wheel by misting or splashing inside the chain case then exiting around the drive sprocket behind the clutch.

Referring to Richardson @ page 62 I am in mid-stream of installing an Main shaft Oil Seal and have come across a couple of interesting things.

1. The main bearing carrier in E1/4 is carried on a number of fingers or webs. This seems to me that even if the main bearing seal is fitted then oil can still pass without restriction from the crankcase thru the galleys in between those webs. The seal carrier when installed does NOT seal these galleys –So why bother with the oil seal on the bearing?

2. The seal carrier has a shoulder on it that fits into the hole in E1/4 where the bearing is located and that shoulder is 0.143” high. The conundrum is that the bearing itself is retained by a circlip ET125 and that circlip is just 0.093” below the face of E1/4; this means that when I do try to install the seal carrier the shoulder on the back of it strikes the circlip, preventing further insertion, well before the outer body of the seal carrier can bear on E1/4. I did consider what may happen were I to remove the circlip and rely on the seal carrier to retain the bearing but the outer face of the bearing is 0.176” below the face of E1/4 thus this would then create a space between the seal carrier and the bearing, of 0.033”, where now the bearing is snug up against the existing circlip.

3. In passing I should mention that I was supplied with E236, the seal carrier for the twin, not E229 which is for the Comet. I figured the only difference was the location of the holes for the retaining screws, so I simply drilled new retaining screw holes in it. Should I be dumping the now modified E236 and replacing it with E229?

I really would appreciate learning how my fellow Comet custodians have approached this matter.


  • Is fitting the seal going to have any impact on the passage of oil from the crank case into the chain case?
  • If you have successfully fitted the seal has it reduced – or better, eliminated, engine oil getting into the chain case?
  • Were you able to get the seal carrier to fit snug against the face of E1/4? How?

I have photo’s of the area if anyone is interested.

Martyn
 

davidd

Well Known and Active Forum User
VOC Member
I am a little confused with your description. This is an add on piece that does not "fit into" anything. Once the seal carrier is glued and screwed to the case there is no way for oil to escape except through the seal. The seal rides on E216/1, which is an E216 that has the OD ground to take a seal. Any owner running a dry clutch must run this seal. The carrier was made in the shop so I cannot comment on twin v. single.

OilSealComet1.jpg


David
 

Martyn Goodwin

Well Known and Active Forum User
Non-VOC Member
David,

thanks for the photo - it shows more than I have revealed in my strip down.

The remaining issue is the shoulder on the seal carrier striking the circlip in fromt of the bearing. Close (magnifing glass) examination of the illustration in Richardson reveals that this circlip has been removed. This would solve the problem!

Did you remove the circlip??

Martyn
 

davidd

Well Known and Active Forum User
VOC Member
I am reasonably sure that I used the circlip. I can't remember the back side that well. I would have said that the shoulder is just deep enough to locate the carrier so that it is concentric with the case and shaft, but that it did not fowl the circlip.

David
 

craig

Well Known and Active Forum User
VOC Member
You remove the circlip. The circlip will not permit proper fitting.
You may find the circlip groove is nicked up and you will have to scrape it to achieve a round bore.
You may have to trim or grind the OD of the new seal carrier flange to fit into the off center bore of the primary. You simply need adequate clearance to allow centering in the bearing bore.
My seal carriers have been so tight in the bore that i drilled and tapped 2 holes in the new seal carrier flange to allow inserting a slide hammer puller. doesnt require much effort to remove and i prefer the tight fit.
 
Last edited:

Black Flash

Well Known and Active Forum User
VOC Member
when I FITTED THE CONVERSION MANY MOONS AGO; i ALSO HAD TO REMOVE THE CIRCLIP AND THE CONVERSION WORKS A TREAT:
sorry I just noticed I was shouting

Bernd
 

davidd

Well Known and Active Forum User
VOC Member
Thank you Craig and Bernd for clearing that up! Bernd is running a dry clutch aslo.

David
 

Martyn Goodwin

Well Known and Active Forum User
Non-VOC Member
Thanks to all for the feedback. After careful consideration I have decided to leave the circlip in place. I figure its there to stabilise the bearing and control end float of the crank. Based on my measurments of my bike and the bearing holder from the VOC, if I removed the circlip then installed the seal carrier there would be end space - thus the opertunity for end float - of around 0.045 " between the bearing and the inner face of the seal carrier. Additional - all that would then be controling the end float when (not if) the bearing moved, would be 3 small 3/16" screws.

What I have decided to do is mill down the inner face of the seal carrier so that the step is no greater than 0.090", thus allowing it to be installed with the circlip still in place.

Will get back to this thread once completed with a synoposis of the work and results.

Martyn
 

stumpy lord

Well Known and Active Forum User
Non-VOC Member
You will allso have to adjust the outer flange of the garter seal to clear the circlip where it peeps out from behind the seal carrier.

stumpy lord.
 

Martyn Goodwin

Well Known and Active Forum User
Non-VOC Member
Hmm, I thought I may have a problem with the eyes of thecirclip as well because they do peek out behind the seal carrier but I havedouble checked all the dimensions and those eyes are well clear of the spacerE216/1 that goes into the centre of the seal G24 and as the seal itself doesnot move (nor does the circlip) then I believe all will be well – as I expect Ican position the actual body of the seal in the carrier so that the seal itselfshould just miss touching the circlip and its ears by approx. 0.003" whilestill having both of its sealing lips in contact with the spacer. BTW there is plenty of clearance between the circlip and the OD of the E216/1 spacer with no possibility of contact between the two.
Tomorrow I plan to do more work on modifying the seal carrier itself as outlined in my last reply. Fingers crossed all will work out!
It strikes me that the seal carrier ET236 could do with aminor redesign, something I intend writing about once I have successfully finishedthe installation of the seal on my Comet.
 
Top