CV Axel confusion.
 

Took my passenger side cv axel out on my 20th AE 5 speed cause the boot was ripped and was just gonna replace it. Did it and had a leak. Replaced the seal and still leaked. I noticed the new cv I purchased didn't have the little cup/cone like seal that (looks like) sits in the seal on the transmission but is mounted on the actual cv itself. So I took it off the old core and kept it. Should I use It? Put it on the axel to stop the leak? Only reason I haven't is because it's a little bent and I'm skeptical about it. I don' know where to buy another one. Is its absence of that cup/cone seal on the axel causing my leak? I have a hard time finding the correct diagrams online but have been told the cup/cone seal is irrelevant. Please help.

It protects the oil seal and isn't completely necessary. Reuse it if you can. Don't fret if you can't.

That little cone is more/less a shield for water/dirt to keep it away from the seal itself, it doesn't seal the liquid. If a new seal is leaking with a new shaft there is either an installation problem, a part problem, or an alignment problem.

An alignment problem points to larger issues with the diff bearings, hopefully that's not your issue.

When installing, make sure you drive the seal in squarely, and apply a small amount of grease to the seal prior to inserting the axle.

If you replaced the seal and you still have a leak it's possible your differential bearings are shot. It happened to me.

Maybe the old seal leaked because it got damaged during the change. Maybe the new seal leaks because it it the left side seal that has a larger opening, 1.535 inches vs 1.299 inch.

Is you car elevated in the front when you fill the transmission case? On one of my 5 MT 4th gens, we had been overfilling the transmission because the front was elevated at the time we filled it. We changed 3 seals before we figured out we had been overfilling the transmission.