gearbox breather/ filler

[townsends20]

 can someone tell me if this is a bsa fitting, this is on a rr2t box.
     steve.
West Sussex

[rocket man]

hi that  has been  modified   not a standard thing to have on gearbox

dave

[alanp]

Darn good idea though considering that on long runs the inside of the box must get hot and pressurised.
Alan

[KeithJ]

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? 
ATB Keith

[chaterlea25]

HI Keith,
In most cases theres enough clearance around the clutch arm pivot to allow
some breathing take place

HTH
John

[KeithJ]

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"?

[chaterlea25]

Hi keith,
As such BSA did not include a breather
I have seen various attempts at adding some kind of vent hole

John

[WozzA]

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...   

[KeithJ]

"What about the speedo cable?   I bet air gets in there...  I know OIL gets out...    "

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

[WozzA]

Yeah the O ring is fitted...  90 MPH eh?  I dont think I'll ever have mine up there,     
BUT the oil spots on my shed floor are witness to what I suggest are true..   

[Dean]

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 

[KeithJ]

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 

Er!  Main bearing 'seal' should seal f not it leaks ?  Or does it act as a 'flap seal'http://www.a7a10.net/forum/Smileys/default/icon_eek.gif

[duTch]

 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.

[orabanda]

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

[KeithJ]

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