Russ,

Try it now and see if it stops the leak. The oil itself is often enough to make it stop enough to get the gear moving. Then you can put some cycles on it and get it to start seating.

You can replace the O rings on some gear, but generally, they are a pain to take apart... At that point, I'd be inclined to sent them back and get the manufacturer to fix them. Who's gear is it?

Bob