gearbox oil leak

spyda

New Forum User
Non-VOC Member
i have been chasing oil leaks on my twin after outsourcing the rebuild and one by one seem to be getting there.
However the gearbox is still giving me grief and i've done a couple of improvements and have a couple of other ones to tackle to try and solve the problem.
this got me thinking about grades of fluid in the hope that if say things are warped in the g50 plate area or something is just not repairable short of a motor strip down/machining job in the meantime does anyone run a semigrease solution that simply wants to stay in the box.
I'd rather fix the leaks of course but also thinking out side the square
 

Marcus Bowden

VOC Hon. Overseas Representative
VOC Member
How long is you dip-stick spyda ? The one into the gearbox, the end of mine is drilled to take a length of Bowden cable (throttle size) to reach the bottom of your box so one can keep check of the oil when not reaching the dipstick, mine stays the same year in and out, if I put level to mark in dipstick it is gone in a few thousand miles. So long as the cogs teeth dip into it every thing will get lubricated. Also have a kickstart cover drain plug 1/4" BSW that lets out water and oil that accumulates.
bananaman
 

jellywrestler

Well Known and Active Forum User
Non-VOC Member
have replaced the gearbox seal and it happens when parked, i'm still keen to trace the fault just worried about running to low on oil in the meantime also was sure Marcus's theory on running oil lower is OK but wanted to check others theories.
I've haven't been able to log on here for over a year so started another account hence the two person discussion...
 

timetraveller

Well Known and Active Forum User
VOC Member
A simpler solution to letting oil and/or water out of the kick starter cover than that given by Marcus above is to just file a 'V' out of the rear face of the cover at the low point. It is not visible and does the job and I have been doing it for years with no adverse effects. I also countersink the hole behind where the G40 shaft goes through the G50 back plate and fit a well greased 'o' ring there to stop oil migrating along the shaft and into the kick starter cover.
 

spyda

New Forum User
Non-VOC Member
one would expect you've worked the lengths out when the clutch was out and you could see in the side, dont want to go to that trouble so how long is the cable bit and how far below standard dipstick is safe to run the oil?
what grade of oil is the norm these days, and brand while i;m asking.
cheers Marcus
 

greg brillus

Well Known and Active Forum User
VOC Member
Fill the gearbox with one liter of 80w/90 hypoid gearbox oil, usually just touches the bottom of the dip stick. One most common leak is out of the bushes between the G3 main shaft and the output shaft G4, namely the G17 bush. If you gently bump the bush in slightly and fit an "O" ring into the gap and the G26 spring cup will hold it in place and slow the leak somewhat. A proper lipped seal can be installed, but requires machining whilst the shafts are out and in your hands....not what you are wanting at this stage....but the O ring will help.....cheers......Greg.
 

Gamecio

New Forum User
VOC Member
New to Vincents and this forum. I have a newly rebuilt Rapide engine that seems to be migrating gearbox oil into the kickstarter case. I'm aware that there is no gasket on the kickstarter cover and after reading this post, am now thinking that there should not be any oil in that area. Please confirm and thanks for any replies.
 

Gamecio

New Forum User
VOC Member
No, not even to bottom of dipstick. I did squirt some oil in there (per rebuilder's recommendation) because the kickstarter was getting stuck and wouldn't budge. I now believe that the first tooth on the kickstart quadrant needs to be filed down as per video on this site. It just seemed like more oil was coming out than I squirted in but maybe not.
Thank you Bruce for the reply, I now know for certain that there should be no oil in there. I will need to monitor the situation.
 
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