I have a problem, I have replaced an axle seal twice after replacing a CV shaft with a remanufactured one on my S51 manual transmission. I can assure that the seal has been installed properly and it is the correct seal. Could the cause of this leak be from a poorly machined Autozone reman (cardone) axle? I'm thinking that the mating surface area on the shaft is not creating a sufficient seal, thus causing a leak. Is that feasible? I am hating gear oil very much after this one!

 

It is possible.
You could try another manufacturer or have a trusted mechanic take a peak for you to verify.
Did you replace the seal yourself?

 

My best friend is the head mechanic at my shop, and i was there with him when the 2nd seal was replaced. I was told by a couple folks that this could be the issue. It did not leak when the original shaft was in the vehicle. Thank you for the reply. I will try a brand new shaft from an alternate source and give an update. I feel that I am not the only one who has experienced this issue.

 

Sorry to hear about the trouble.
I think returning the 'defective' one and trying another brand is the right choice.
Please post back with your results.