I replaced the driver side axle seal on my car. I thought maybe the National Oil Seal I used was garbage, so I popped that out and put a GM axle seal in. Still leaks. Used the GM Kent Moore tools for install btw.

Any ideas?

 

Bent axle???

It may not be applicable here due to a difference in design but my Toyota kept blowing axle oil seals and it was a slightly bent axle. With super swamper tsl's and leaf springs i couldn't notice the vibrations i would expect with a bent axle

 

I was thinking maybe the part where the axle goes into the trans is worn. It was shiny and scored when I inspected it.

 

Where the metal lip is. Apply a tiny bead of The Right Stuff. Enough to seal the metals and keep away from internals. As for the inner sid eof the seal leaking. Replace the axle or half shaft. Or sleeve it if u find a sleeve for the shaft.