The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Gearbox, Clutch, Primary => Topic started by: townsends20 on 27.05. 2011 19:31

Title: gearbox breather/ filler
Post by: townsends20 on 27.05. 2011 19:31
 can someone tell me if this is a bsa fitting, this is on a rr2t box.
     steve.
West Sussex
Title: Re: gearbox breather/ filler
Post by: rocket man on 27.05. 2011 20:05
hi that  has been  modified   not a standard thing to have on gearbox

dave
Title: Re: gearbox breather/ filler
Post by: alanp on 27.05. 2011 21:00
Darn good idea though considering that on long runs the inside of the box must get hot and pressurised.
Alan
Title: Re: gearbox breather/ filler
Post by: KeithJ on 25.02. 2014 13:00
If a seal is put on the gear lever and kickstart spindles and a seal on the output shaft, how will the gearbox breath?  How does it breath as standard?  Is the "breathing" the reason for the "leaks" around the various shafts?  Any suggestions for a "good breather" set up?  *conf*
ATB Keith
Title: Re: gearbox breather/ filler
Post by: chaterlea25 on 25.02. 2014 20:50
HI Keith,
In most cases theres enough clearance around the clutch arm pivot to allow
some breathing take place

HTH
John
Title: Re: gearbox breather/ filler
Post by: KeithJ on 25.02. 2014 22:06
HI Keith,
In most cases theres enough clearance around the clutch arm pivot to allow
some breathing take place

HTH
John
I was aiming to put a seal on this as well!  :(  So is the reason oil leaks from various spindles etc there is no formal "breather"?
Title: Re: gearbox breather/ filler
Post by: chaterlea25 on 25.02. 2014 22:43
Hi keith,
As such BSA did not include a breather
I have seen various attempts at adding some kind of vent hole *eek*

John
Title: Re: gearbox breather/ filler
Post by: WozzA on 26.02. 2014 00:09
HI Keith,
In most cases theres enough clearance around the clutch arm pivot to allow
some breathing take place

HTH
John
I was aiming to put a seal on this as well!  :(  So is the reason oil leaks from various spindles etc there is no formal "breather"?

What about the speedo cable?   I bet air gets in there...  I know OIL gets out...    :o
Title: Re: gearbox breather/ filler
Post by: KeithJ on 26.02. 2014 08:46
"What about the speedo cable?   I bet air gets in there...  I know OIL gets out...    :o"

Do you have the O ring fitted? 

Breathing only works via the speedo at speeds over 90 mph.  Can't get past the oil in the cable and the pressure caused by the head of the speedo!http://www.a7a10.net/forum/Smileys/default/icon_biggrin.gif

Title: Re: gearbox breather/ filler
Post by: WozzA on 26.02. 2014 12:01
Yeah the O ring is fitted...  90 MPH eh?  I dont think I'll ever have mine up there,     *dunno2*
BUT the oil spots on my shed floor are witness to what I suggest are true..   *doh*
Title: Re: gearbox breather/ filler
Post by: Dean on 26.02. 2014 16:42
Looks similar to a Landrover differential breather I got once with the thought of doing the same. Then decided the main bearing seal did the same job anyway  *smile*
Title: Re: gearbox breather/ filler
Post by: KeithJ on 26.02. 2014 16:53
Looks similar to a Landrover differential breather I got once with the thought of doing the same. Then decided the main bearing seal did the same job anyway  *smile*
Er!  Main bearing 'seal' should seal f not it leaks *conf*?  Or does it act as a 'flap seal'http://www.a7a10.net/forum/Smileys/default/icon_eek.gif
Title: Re: gearbox breather/ filler
Post by: duTch on 26.02. 2014 23:56

 Something I'd also considered, also for the chaincase.
 Thought maybe an extension on the filler/inspection cover with a flap valve.....??

 I have one of those fancy aftermarket (triumph) screw in tappet covers the right size for chaincase to try.
Title: Re: gearbox breather/ filler
Post by: orabanda on 27.02. 2014 03:43
I drill a small hole in the upper rear of the chaincase (just forward of the long magneto bolt), and push in a 90 degree plastic yamaha breather adaptor (as fitted since the 70's to the DT and RD range). It is cheap, and very compact (and durable). Then push a short hose onto this. Relieving the pressure in the chaincase by doing this, in conjunction with lapping the inner and outer chaincase surfaces, and fitting fibre washers under the drain screws, will ensure the case doesn't leak. 

Am overhauling another gearbox, and intend to install the same Yamaha adaptor in the top of the gearbox (hidden under the ski slope) with a short hose routed towards the swing arm.

The adaptor is a push-in fit; the hole size is approx 6.5mm.

Richard

Title: Re: gearbox breather/ filler
Post by: KeithJ on 27.02. 2014 08:15
Can you pst the part number for the Yamaha breather so we can find out what it looks like?  Is it a "one way" type or just open to vent?

Thanks
Title: Re: gearbox breather/ filler
Post by: orabanda on 27.02. 2014 09:25
Hi Keith,
Check out link.

http://yambits.co.uk/dt100-usa-crankcase-gearbox-breather-kit-p-50864.html


Richard
Title: Re: gearbox breather/ filler
Post by: orabanda on 27.02. 2014 09:37
The pic shows where Yamaha fitted  two on a DT360A; the front one is venting the magneto chamber, while a second one behind the carby is venting the gearbox.

Compact and tidy.

Here is a link to the genuine item on Ebay.

http://www.ebay.com/itm/nos-yamaha-snowmobile-motorcycle-crankcase-chain-breather-mx-rd-rt-dt-yz-ty-srx-/111196230548?pt=Snowmobile_Parts_Accessories&hash=item19e3cfd394&vxp=mtr

Regards,
Richard
Title: Re: gearbox breather/ filler
Post by: Dean on 02.03. 2014 16:45
Looks similar to a Landrover differential breather I got once with the thought of doing the same. Then decided the main bearing seal did the same job anyway  *smile*
Er!  Main bearing 'seal' should seal f not it leaks *conf*?  Or does it act as a 'flap seal'http://www.a7a10.net/forum/Smileys/default/icon_eek.gif

You are quite right Keith. I was having a senior moment and thinking of the felt seal behind the clutch. Only excuse is the issues I had with felt seals in the Trike. Just what you don't need when the seal is supposed to keep the oil from the pressurised diff from getting on the single front brake drum (which its doesn't *eek*)
Title: Re: gearbox breather/ filler
Post by: KeithJ on 02.03. 2014 17:32
Hi Keith,
Check out link.

http://yambits.co.uk/dt100-usa-crankcase-gearbox-breather-kit-p-50864.html


Richard
Looked at the site and was going to get one but they wanted more to send it than the cost of the item.  So will look for an alternative.  Appreciate the post.  ATB  Keith  *beer*
Title: Re: gearbox breather/ filler
Post by: duTch on 02.03. 2014 21:25

 You might find stuff like that in a irrigation or fish tank shop? May not be oil/heat friendly, but cheap..
 
Title: Re: gearbox breather/ filler
Post by: duTch on 23.07. 2018 23:54

 Keith- I'm just wondering how you got on with this episode...?
Title: Re: gearbox breather/ filler
Post by: KeithJ on 24.07. 2018 07:40
Have not done anymore on it.  Been using the bike, good new and sorting out other issues bad news.  Other issues largely due to problems with new parts.  Now up to 3000 miles since full rebuild.  ATB
Title: Re: gearbox breather/ filler
Post by: duTch on 24.07. 2018 09:40

 yeah ok, I've been drilling holes in things i maybe shouldn't be but will see what happens....I'l try and remember to let you know *pull hair out*