passenger side cv starts leaking after 6 mo.

I've replaced the passenger side cv seal twice now. I've watched utube videos and I'm sure it was put in correctly. But after 6 to 8 months it starts a slow drip leak. Any ideas what i'm doing wrong?

 

Is it still the OEM CV or aftermarket? Might have a problem with the stub shaft that goes into the differential, like a nick or some sort of damage or if aftermarket, maybe it's not the correct size by a small amount and allowing oil to escape.

 

Are you sure you got the correct seal in the diff?

 

Did you sand away rust on the torque tube inside diameter where the seal sits?

Did you verify the front diff breather isn't clogged?

 

You gotta just barely seat it, then use the CV to finish seating it to correct depth. Trying to guess the depth will always cause a leak.