Hi, Scotty, 

First, I love your channel. Thanks for your 53 years of mechanic experience!!!

I have a 2011 Mazda CX9 touring, all wheel drive. It has 95k miles on it, and three months ago, I replaced the transfer case gear oil. Nobody replaced it before me, so it was burnt. I sucked it up and put fresh oil in, and I drove 1000 miles before checking under the car. It was leaking. I figured out it was leaking from the top of the transfer case. It looks like it's coming from a plug,  but I dont think it's actually a plug. It wiggles when I touch it. Also, when I drive down steep hills and brake, it downshifts from 4th to 3rd gear. My question to you: Is the transfer case bad, and does it need replaced? Or is it normal to leak from the top? Also, do you think the downshifting downhill is from a bad transmission, or is that normal? Finally, if the transfer case and/or transmission is bad, is it better to pay to fix them, or should I just get a new car?

Thank you for your help!! Always wish you the best!

-J.C.