oil cross contamination

[desratt]

I have searched everywhere..

my tranny oil goes dry and the engine oil overflow's

what do I do???

[eastside 400]

crank seals are bad. the one you can change by taking the cover off but the other has to be done by splitting the cases. should be able to take the clutch basket off and change that seal, if im thinking of this right that should be the only one that would cause the oils to mix

[desratt]

heard on the bikes. sometimes it's the countershaft seal. one makes the oil go toward the tranny and the other makes the oil go to the crankcase..they didn't know which...thought surely someone has had this happen...

also where is the tranny vent??? some one said make sure it is not clogged and building pressure in the tranny.

[eastside 400]

i know on the 05's its by the kicker on the case at the top.

[turbo j]

Yep, its either the right side crank seal or counterbalancer shaft seal. Just had to do mine. These seals are relatively cheap so buy two when you order. I damaged a new one putting it in until Igot the hang of it. Make sure you have a manual if you are going to do it yourself.

[hillbillyhpower]

so could the clutch side seal cause oil in the airbox?

[Sjorge450R]

you are getting oil in the air box for one reason. too much pressure in one side of the motor which then causes it to vent into the breather which is routed into the air box.

[hillbillyhpower]

well, i changed the clutch side seal and the tranny side and motor side oil still pumps out. with a brand new piston and rings, blow by makes no sense at all.

[rt20ps]

Is your oil still migrating from clutch side to engine side?? Did you change the couterbalancer shaft seal?

[hillbillyhpower]

no, everyone told me "change the crankseal behind the clutch basket" so thats what i did. same thing, air filter full of oil. now i have a wonderful noisy 3rd gear, the end is prob near for the trans, AGAIN.

[desratt]

here is a question of possibility...
what is the purpose of the reed valve inside our crank case???

[hillbillyhpower]

reed valve? never hear of such thing in a 4stroke. not that i dont believe you?

[pro-rider46]

the reed valve is a one way valve, it lets oil go through one way, and not the other.

on my crf, the right side crank seal went bad, and did exactly what your saying, i put a new one in and it fixed the problem. another thing you can look at is the whole right cover gasket, if it isnt aligned properly it will mix the oils together too. but will flood the tranny, when my crfs seal went it flooded the engine side and came out of the crank vent, or the valve cover vent and filled my airbox.

[hillbillyhpower]

thanks, i am splitting the cases again due to 3rd gear noise. maybe something obvious will be detected