Did Route 66 with my car... Took it on a short accidental offroad adventure... Help?
 

Well I took my car on a 2000 mile trip from Columbus Ohio to Chicago to Flagstaff AZ, and had a great time. At one point we were on a little mountain road between Albuquerque and Santa Fe, and I had to turn down a random road to check my maps. The road was dirt, but not in bad condition, and it was just to turn off for a second. As I made a U turn I slipped into a big rut in the road that was almost invisible in the sunset, and something scraped big time. A few minutes later an awful groaning noise was coming from the left rear area around every turn and over every bump. It didn't seem to affect how the car drove so we continued on to Flag. Now I'm sitting in Flagstaff with my car at the shop and I get a call from this new slick mechanic. He tells me that the noise in the rear disappeared and that there is a new noise coming from the Swaybar endlinks (I have strano sways) and the rear diff is leaking. I drove the car from Santa Fe to Flagstaff and noticed no noise from the front and I looked under the car several times and saw no leaks. I'm a new college freshman and this mechanic knows it, thanks to my parents, and I think I'm getting played here. I'm leaving in like 10 minutes to go listen for a noise in the front, but I feel like I would have noticed this over the last few hundred miles. Does anyone have any advice or knowledge?

You may have just picked up some dirt and grit into the brake-rotor that worked it's way out. I would find a place to jack it up, remove the wheels and look around for anything that looks scraped or bent. Make sure you block the wheels to keep the car from rolling and use a jack stand to hold the car up. You can actually see and feel the brake rotors without removing the wheels or jacking it up, do not touch them until the car has set for 10-15 minutes, they can get pretty hot. If you see or feel a ridge in only one rotor it's prob fine now. If you see anything bent, you'll prob need to take it to a trusted mechanic.

Yep... sounds like dirt or a small rock got into something it would rub on. Happens alot with brake rotor covers.

Also...if the leak is around the area of the differential vent tube....you are most likely ok.

You could have bent a lower control arm. Contrary to popular belief, all mechanics aren't out to screw you over.

You wouldn't see the rear end leaking. If it's the pinion seal, then it's only going to leak while you are moving.

Doesn't sound like you hit too hard, so most likely some dirt / gravel got in the works.

Take a look at your differential and feel for oil. It maybe a small enough leak that it doesn't trickle all the way and hit the ground. It's not always gushing out.

Soooo.... What happened here OP?