Chronic Countershaft seal leak

I have an 01 426 , that no matter what I do, I can not get the countershaft seal to stop leaking. I have replaced the seal, the oring, and the bushing and it still continues to leak. I was very carefull while installing the seal and the oring, so as not to damage them. I coated everthing with new oil prior to installing the spacer/bushing(that sits behind the sprocket). I also inspected the shaft for nicks or burrs that could damage the oring, and found nothing. I am hoping someone has had a similar problem and found a solution. Right now, the only thing I can come up with is that being new to the fourstrokes that I am over servicing the engine with oil, and that the extra oil has to go somewhere. I have been following the manual as far how much oil is required and how to check the level. I am a mechanic and know that oil literally is the lifeblood of these engines, and suggestions would be greatly appreciated. thanks

:naughty:

If you have ever had the chain TOO tight (it should be about 4 fingers sloppy at the end of the swingarm rubber) and hit a jump, bump or whatever, it may have bent the shaft ever so slightly. If that's the case, which i suspect it is, you'll either have to replace it or just live with it.

The first thing is to double check that the leak is actually coming from the output shaft. Other possibilities on that side are the neutral switch, clutch actuator, shifter shaft, and even around a case bolt

If it is, then I suggest checking for vertical/horizontal play (perpendicular to the shaft axis) in the output shaft left hand bearing. Should be very little. Too much, and the seal won't be able to cover the motion.

Too much oil will not cause this in a dry sump system. You should be using a total of 1.7 liters of oil. Until you exceed about 2 quarts, nothing of any note will happen. Beyond that, the return pump will not be able to fit it all in the tank, and the extra is forced back into the engine by way of the pressure balance tube between the tank and cam box. The first symptoms are usually smoke and excess oil in the breather.

My countershaft seal has been leaking since the day I got my bike basically. I finally got around to it to figure out that it was the counter shaft leaking last week and i bought a new seal and o-ring, and the dealer told me to put some grease on that seal when you put it in which seems to make sense that the grease would help make sure it is completely sealed. its been really crappy and i have a ton of homework as its only a week away from finals so i havent got around to it yet but hopefully next wed. i'll be done with finals and get that new seal in and give you an update

If it is, then I suggest checking for vertical/horizontal play (perpendicular to the shaft axis) in the output shaft left hand bearing. Should be very little. Too much, and the seal won't be able to cover the motion.

Another point on this is if the lip of the seal is not pressed in square, or the face gets deformed the lip will act like a pumping ring and always leak. You should whenever possible use a press to install lip seals. Great care should be taken when you can't. It can be done with a socket and hammer but not nearly with the same level of quality.

Thanks everyone for the quick responses. I am 100% sure that the its the countershaft leaking. While replacing the seal and the oring, I did the shift shaft seal and the neurtral switch o-ring as well(just in case it wasnt the countershaft) I am going to check the the shaft runout with a dial indicator and see if it is tweaked as well as check the bearing for play. Thanks again and I will let you know what I come up with.

I have the same problem and it is absolutly rediculos.

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