Leak - any ideas?

Gelandestrasse

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Looks like my gearbox joint has sprung a leak (2010 GSA). It's not coming from the shifter seal. Is this common? Live with it or fix it?
 

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What’s it like underneath ? Wet with oil ? It’s usually a leaking balance shaft seal.
 
Where's the balance shaft seal?

Which is the balance shaft seal, please? Presumably it's on this diagram?
 

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Which is the balance shaft seal, please? Presumably it's on this diagram?

Nope. That’s the gearbox, the balance shaft is in the engine and the seal is at the back of the engine accessible with the gearbox removed.

What does the oil smell like. The difference between engine oil from a leaking balance shaft seal and Gear box oil from a leaking gearbox have very different odours.
 

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If either the balance shaft or crank shaft seals are leaking, then you can remove the starter motor to have a look. Any leaks will be obvious.
 

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Stick a new clutch in there while it’s apart…


You’ll thank me later

Jesus Christ!

The OP hasn’t worked out where the leak is coming from yet, whether it’s an internal or external leak or whether it’s from gearbox or engine, and you’ll have him change his clutch. :blast
 
Looking at the diagrams above, the leak is dripping onto the exhaust hanger (top picture). The balance shaft and its seal is in the bottom photo, black engine. The balance weight seems to spin in the large recess in the first diagram, roughly between the numbers 8 and 12, directly beneath the gearbox input shaft (splines).

So if it's coming from the balance shaft seal, how does it get to the exhaust hanger (don't say the wind can do it, as the bike hasn't moved quickly for some time). Isaac Newton says 'no'?


I did whip the battery out to make sure that wasn't leaking - it isn't.
 
You can see it’s also “ misting” from the bell housing joint,
It will be the balance shaft seal.
Either way,to fix it is a bit or a job.
In reply to the above post” whilst it’s apart”.
A 1200 clutch is not cheap
.
 
Why don’t you.

A. Establish what type of oil it is. Engine or gearbox.
B. Thoroughly clean the area around the suspect leak.
C. Take the bike for a long run in good weather.
D. Then have a good look in and around the area post ride.

A little bit of hot oil travels a long way. What you have is a little bit of oil.
 
How hard can you make it?
There is oil.
It’s coming from the the engine / gearbox joint.
The only way to confirm is to split the bike.
Two specialists that work on these things day in,day out,suggest that it’s the balance shaft seal,why do you think that might possibly be.?
Either way whether it’s the gearbox seal,balance shaft or rear main,,the op needs to deal with it or risk fucking the clutch up at some point due to oil contamination.
Of course it could be the the clutch slave cylinder pushing fluid into the bell housing,or all four.
Cleaning it off won’t confirm much
 
Looking at the picture in post #1, I take it that the two joined parts we can see is the joint between the two halfs making up the gearbox housing.

This leaves us with the following potential leaks from:
- The joint between two halfs of the gear box housing
- Gear shift leaver
- Shaft for the gear indicator potmeter (closest to where the oildrip is spotted)
- Two more shaft seals at the rear of gearbox
- Gearbox oildrain plug.

Whatever the source for the leak is, the chances for having to remove the gearbox are way above average, and if so, I am on page with @popel that changing the cluth plate is a good idea (unless the bike is a low milage bike for it's age).

And also, while apart, it would be time well spent to inspect the seal for the engine output shaft as well as the seal for the balance shaft.

Oil seals are dirt cheap compared to the effort it takes to dismount the gearbox, and if this was my problem, I would have changed all the oil seals, regardless of where the leak came from...
 
I priced one up when my slave cylinder imploded. Over £500 for main parts.

If the clutch is in working order, changing the friction plate will do.

From MotoBins, we are talking £ 116 for an OEM plate, and half the price for a good none-OEM plate...
 
My clutch fluid is blue.


The leaky oil is brown/gold. My sense of smell isn't good enough to tell if it's engine or gearbox oil, but it seems the gearbox will need to come off anyway...

Naturally the clutch will be checked while I'm there. If it isn't broke I won't fix it though. 44k miles on the bike; we'll see what condition it is.
 
My clutch fluid is blue.


The leaky oil is brown/gold. My sense of smell isn't good enough to tell if it's engine or gearbox oil, but it seems the gearbox will need to come off anyway...

Naturally the clutch will be checked while I'm there. If it isn't broke I won't fix it though. 44k miles on the bike; we'll see what condition it is.

I know what a horrible job the clutch is and I deliberately never gave it a hard time - but it let got at 32k miles - dealers first words were has the rear main seal gone... if you go for a long high speed ride it seems to dry out / fling the oil off the clutch and it works for another 1000 miles no issues.... 4 years on I'll get around to it one day

in between at 35k miles the swinging arm bearings have just self destructed and last weekend I find the back wheel is trying to fall off now - and my third tail light just snapped the lower third silly fastening where it just auto self destructs - it did that first at 8k miles and 2 years 2 months old. When I said they are paying they said no they aren't - I said yes you are, I have 40 year old Jap bikes and the tail light has never fell off any of them !!!!!
 
Well I sniffed really hard at the oil drip that had accumulated and it is gearbox oil. So there’s another job to add to the many I have on this bike.
 


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