This is the inboard CV, the one bolted to the transmission, correct? CVs don't have oil in them, so Your Problem is you have a leaking transmission seal. Fortunately for you, the seal that's leaking is right under the CV, it costs three bucks and you can change it with the transmission still in the car. Just pry it out and put in a new one. Or better, pry both of 'em out and put in new ones. The one on the other side is the same age. Just that once a boot starts to leak you only have a sort distance to replace the boot or replace the entire CV-joint. If even a little contamination gets in the joint it will fail rapidly. Sometimes it is better to just replace the entire half-shaft rather than take a chance of needing to do the whole job over.