The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Gearbox, Clutch, Primary => Topic started by: orabanda on 17.11. 2008 09:51

Title: A10 semi-unit primary case oil seal
Post by: orabanda on 17.11. 2008 09:51

Hi all,
I wanted a better (and more easily serviced) primay case - gearbox oil seal, so came up with this arrangement for my semi-unit bikes.

(https://www.a7a10.net/forum/proxy.php?request=http%3A%2F%2Fi302.photobucket.com%2Falbums%2Fnn82%2Forabanda%2FA10enginecluchseal.jpg&hash=9c7b87c5f96d5c5ce17c8fc98a9e2f9375ee9648)

I bored out the alloy casing, until the three rivet holes cleaned up

(https://www.a7a10.net/forum/proxy.php?request=http%3A%2F%2Fi302.photobucket.com%2Falbums%2Fnn82%2Forabanda%2FA10clutchsealcarrier.jpg&hash=6c5daefc8b3d2e6712f4dd0fef0613dd2c3d0dca)

(https://www.a7a10.net/forum/proxy.php?request=http%3A%2F%2Fi302.photobucket.com%2Falbums%2Fnn82%2Forabanda%2FA10clutchsealcarrieroutsideview.jpg&hash=a39ddacb7c90813bf6f5ada50fe4801a02912e4f)

Then made 2 x halves threaded male and female. The outside half is an interference fit; however, both halves lock in when done up anyway.


Regards,

Richard

Title: Re: A10 semi-unit primary case oil seal
Post by: Richard on 17.11. 2008 18:37

I was impressed with this and was talking to Bill Little this afternoon about it
However does the advantage of easier seal replacement justify the time and cost of this exercise bearing in mind that the seal replacement is something that does not require doing very often
Respect
Richard

Title: Re: A10 semi-unit primary case oil seal
Post by: a10 gf on 08.04. 2013 12:36

Just seeing this for the 1st time! Excellent work indeed.

Title: Re: A10 semi-unit primary case oil seal
Post by: renos-a10 on 08.04. 2013 13:04

I will do the same i think in my Plunger!!
Exellent work!!

Title: Re: A10 semi-unit primary case oil seal
Post by: Briz on 08.04. 2013 13:34

I did this 30 years ago! Except I made it big enough to be able to get the gearbox sprocket off too.

Title: Re: A10 semi-unit primary case oil seal
Post by: orabanda on 08.04. 2013 15:38

Gosh, a blast from the past; I had forgotten all about that!

And a perfect result; I don't have leaks from the primary case seal!

Also did this mod for my 51 plunger.

Recently got a '49 long stroke A7, so will do the same for this engine when the time comes.

Here is the donk in the bike; a sweet thing to ride!


(https://www.a7a10.net/forum/proxy.php?request=http%3A%2F%2Fi302.photobucket.com%2Falbums%2Fnn82%2Forabanda%2FP1050213.jpg&hash=7ca3952c3f2834159e6c6978d700a9cee1df130f)

(https://www.a7a10.net/forum/proxy.php?request=http%3A%2F%2Fi302.photobucket.com%2Falbums%2Fnn82%2Forabanda%2FP1050212.jpg&hash=8a16fa87dd6da615855e9bc45a698547e3abb29b)