After following a breadcrumb trail of oil drops from my truck I figured it was time to replace the main seal. It's been leaking for a while and I've been putting it off. Long story short I pulled the old seal and can't see a thing wrong with it. It really doesn't look like it was leaking. I expected oil all over and that it would be obvious. It was never a large enough leak that I had to replace oil. Shouldn't it be obvious?

Also, I replaced the gasket from under the truck. In other words, I didn't remove the seal's "frame". I just pulled the seal and put in the new one (not putting grease around it, mind you <img src="/forums/images/graemlins/evil.gif" alt="" />) taking care to be sure that I didn't fold the seal at all. Should I remove the "frame" and reseat it will grease?