A10 semi-unit primary case oil seal

[orabanda]

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.



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





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

[Richard]

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

[a10 gf]

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

[renos-a10]

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

[Briz]

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

[orabanda]

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!