New 12 bolt pinion seal leaks

[vstol]

While I was replacing the transmission and drive shaft I thought I would replace my rear pinion seal on my 12 bolt in my 72 Camaro. Well it leaks more now than when I replaced it, I will replace it again but what I'm I missing? It has been on the lift since I replaced it and it has not been out on the road does it need some road time to seal better??
Thanks