Internal Bleeding

[Live2Ride300]

Has anybody had a problem with the transmission oil leaking into the crankcase oil and being blown out the crankcase breather hose? I just blew a transmission this way.

[Rich250RRacer]

Originally posted by Live2Ride300
Has anybody had a problem with the transmission oil leaking into the crankcase oil and being blown out the crankcase breather hose? I just blew a transmission this way.

Are you refering to the breather hose that comes from the cylinder/head area? I just had my '07 out for it's second ride today, and after 10 minutes of riding, the left side of the quad was covered in oil. It was at the dealer for warranty water pump seal replacement, and it looked like they overfilled the crankcase. But now you've got me wondering if its transmission oil.

[Live2Ride300]

The breather going into the airbox was spewing oil out. Somehow the tranny fluid leaked into the crankcase oil and high oil level was blew out the breather. I was running wide open all day long.

I've got the cases split and can't seem to find anything indicating how the trans fluid got in there. No cracks in the cases, no damaged oil seals. You should my trans, totaly fried!

Anybody else having this problem?

[Chino886]

Hey Live2ride, can you show us what happened to your tranny, there is tranny problems with the 06 trannies. There has been problems with the shift drums and the "dog ears".

[speedfreaksguy]

I have seen this happen to a few CRF450 motors. It's either the main seal on the clutch side or the couterbalancer shaft seal. Is it possible you overfilled your tranny? This can cause pressure that will allow the oil to blow past the seals. If you already tore the motor down I doubt Honda is gonna do anything for you.

Replace both seals and use a little red loctite on them to hold them in place.

[Live2Ride300]

That's what I've been hearing from everyone bad main seal or counterbalancer seal. Oil was filled to factory spec. I have also been hearing things about hairline fractures in the cases. I built the motor myself, I've done a few 450R engines and never seen this problem, well until this weekend. haha.

I'll snap some fried trans pics when I'm back in the shop.:p

[Rich250RRacer]

Originally posted by Live2Ride300
The breather going into the airbox was spewing oil out. Somehow the tranny fluid leaked into the crankcase oil and high oil level was blew out the breather. I was running wide open all day long.

I've got the cases split and can't seem to find anything indicating how the trans fluid got in there. No cracks in the cases, no damaged oil seals. You should my trans, totaly fried!

Anybody else having this problem?

Mine was spitting oil out of the smaller hose that comes out of the back of the cylinder. This hose runs out by the carb and ends up in a hole in the black tank shield. There was oil covering the motor and my leg.