Gear Box sprocket seal leak?

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dirtymartini

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I finally got my gas tank and side panels back fom my painter, I think he did a great job. Anyway I think my gearbox seal at the FD sprocket is leaking badly. At first I though it was the primary cover but after wiping away the oil it looks to be coming from the sprocket area. I just came back from a ten mile ride and it seems to be worse when the bike is moving. What's involved in changing this seal? Removing the primary and clutch? Can I access the seal then?
Gear Box sprocket seal leak?
 
First, make sure your gear box is not overfilled.

Second, check and make sure the primary drive is not overfilled. Though you may have filled the primary properly, a blown crankshaft seal and add and add and add.
 
Thanks, I thought I may have overfilled the gearbox a bit. The oil does seem to be heavier than motor oil. If the seal has to be replaced what is involved? I may just have to ride it more to see if the leak slows down :D
 
dirtymartini said:
Thanks, I thought I may have overfilled the gearbox a bit. The oil does seem to be heavier than motor oil. If the seal has to be replaced what is involved? I may just have to ride it more to see if the leak slows down :D
Click to expand...

I would take the time to drain/suction/wick out the excess oil rather than rely on running it out through the counter sprocket only because you will be oiling your rear tire whic is not a good thing. Odds are you will probably be just fine but life is too precious to be spending the rest of your life healing.

Been a while since I tore into a gear box but from recollection you can pull and replace the seal by removing the primary drive outer and inner covers and then removing the countersprocket. Clean the area good and pick out the old seal and drive i the new seal.
 
Dances with Shrapnel said:
dirtymartini said:
Thanks, I thought I may have overfilled the gearbox a bit. The oil does seem to be heavier than motor oil. If the seal has to be replaced what is involved? I may just have to ride it more to see if the leak slows down :D
Click to expand...

I would take the time to drain/suction/wick out the excess oil rather than rely on running it out through the counter sprocket only because you will be oiling your rear tire whic is not a good thing. Odds are you will probably be just fine but life is too precious to be spending the rest of your life healing.

Been a while since I tore into a gear box but from recollection you can pull and replace the seal by removing the primary drive outer and inner covers and then removing the countersprocket. Clean the area good and pick out the old seal and drive i the new seal.
Click to expand...

That's what I was hoping for even though it's more work than I want to do right now. I checked the gearbox oil level and it's just below the the hole where it hould weep out for the correct level. I cleaned everything up, I think I'll take it for another nine mile lap around the lake and see how the leak is.
I just had some knee surgery so I don't need any surprises...I'll take it easy.
 
Check the primary oil too, if it's too high, it'll be flying all over in there and get out that felt seal around the counter shaft. Make sure you put some heavy grease on the clutch rod to keep oil from going from the trans to the primary. If you're using syn oil in the gearbox, it will quickly migrate into the primary, loose the syn or get the rod seal kit from atlanticgreen. I used to have all sorts of oil there, but for some reason it's not there now. It will surprise you where oil is actually coming from. I think most of mine was coming out of the primary to crank case seal and blowing back. Once the oil hits the chain it's all over.

Dave
69S
 
If you have a leaking problem at the gearbox seal... then make sure you change the 04-0131 spacer that the seal runs on. I have changed a half dozen of these over the years. They are not hardened and the seal wears a groove in them and if ignored they leak even with a new seal. I also wonder if any oil can get out between the spacer and sleeve gear. A sleeve gear ball bearing with a seal on the outer side can help too.
 
I'l take a look at the primary tomorrow and see how much oil is in there. I think I did put synthetic in the gear box because it was all I had on hand at the time.

DynoDave, thanks for the heads up on the spacer, I'll be sure to order one.

For some reason I don't think this leak is going to go away on its own...
 
dynodave said:
If you have a leaking problem at the gearbox seal... then make sure you change the 04-0131 spacer that the seal runs on. I have changed a half dozen of these over the years. They are not hardened and the seal wears a groove in them and if ignored they leak even with a new seal. I also wonder if any oil can get out between the spacer and sleeve gear. A sleeve gear ball bearing with a seal on the outer side can help too.
Click to expand...


+1 with dyno on the spacer. I have seen grooves in this as well. If you are getting into it this far then put a new spacer in. Its just false economy only to find the gearbox still leaks after a new seal get put in.
CNN
 
Well I drained some excess oil from the primary, drained the synthetic from the gearbox and replaced with regular 90W gear oil. I re-traced my route from yesterday and when I returned to the garage...no leak!
 
dirtymartini said:
Well I drained some excess oil from the primary, drained the synthetic from the gearbox and replaced with regular 90W gear oil. I re-traced my route from yesterday and when I returned to the garage...no leak!
Click to expand...

So was it oil from the primary or oil from the gear box. At this point, who knows - go ride! :)
 
One reason I like ATF in my primary is because the red color makes it so easy to discern from gearbox oil. It also makes it easier to know (aside from sheer volume) if the engine is blowing oil into the primary case.

Glad yours healed itself. Mine stuff never does that...
 
Gearbox oil when filled to the proper level will not rise to the seal level when the bike is level, as in riding

therefore, gearbox oil cannot get out of there

unless

the bike is on the side stand and thus tilting left, then the gearbox oil can just reach the seal

usually this seal is kind of good forever, unless a bike has sat a very long time and the seal gets all dried and contracted with age, and the next time the bike is started and shaft turns the seal can be ripped a little


edit: just stating what I have been told by a couple guys that I respect their Nortoneering know how
 
1up3down said:
Gearbox oil when filled to the proper level will not rise to the seal level when the bike is level, as in riding

therefore, gearbox oil cannot get out of there

unless

the bike is on the side stand and thus tilting left, then the gearbox oil can just reach the seal

usually this seal is kind of good forever, unless a bike has sat a very long time and the seal gets all dried and contracted with age, and the next time the bike is started and shaft turns the seal can be ripped a little


edit: just stating what I have been told by a couple guys that I respect their Nortoneering know how
Click to expand...

Interesting. I just noticed today that my dribbles seem to be worse when on the sides tand. I am due to change all of the fluids. Just because the bike had sat for many years and I probably have about 150 miles on it since put back in service. I think the gearbox had synth so I will go to a standard oil in there. Also, I like the idea of ATF in the primary just for the color as someone else stated. And keep it on the center stand as much as possible.

That seal at the gearbox was not changed since I have the bike.

Is there any sealant that should go on the primary cover to prevent drips there?
 
I also noticed if I leave mine parked on the sidestand in the garage I will get a few drips. If it's on the centerstand no drips. I want to get some miles on it but am waiting for my insurance company to get off it's a** and cover it.
 
Torontonian said:
So that seal is 40 years old ?
Click to expand...

If you are asking about mine, it is entirely possible although the PO did have some gear work done at some point so it may only be 20 some years old. :oops:

Right now, I will just deal with what drips I have and keep in on the centerstand.
 
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