Cagedin

Hi guys, I'm hoping to find someone else who has had a similar problem so I can find a proper diagnosis. I have a 2008 c300 4matic with 79k miles. Yesterday I was driving and the car was jerking while shifting. After a little bit of that, when I hit the gas, it just revved and slowed down. It was as if it was in neutral. I pulled over, put it in park and back to drive. Nothing. When I turned the car off for a minute and restarted it, it would drive again. If I put it into park or neutral with the car running, it would not which led me to believe it might be electrical, as I've had issues with the gas pedal not working after flooring it which was remedied by turning the car off then on again. I let the car sit for an hour and went to get parts for another car. No issues at all. When I returned it happened again, except this time once I would get it started the issue would happen again within a minute. I looked down to see if the car thought it was in neutral. It did not. I called a tow truck. When I got to the garage I backed it in. That's when I heard this clacking noise. It sounded like something was rattling. I believe there is something wrong in the transmission or transfer case, but I don't know what. Any advice is appreciated.

Possibly part of the issue: I have had what I believed was road noise due to cheap tires. It was coming from the rear and was speed dependent. It didn't get worse over 30k miles and putting it in neutral didn't affect the noise so I didn't think much of it. My diagnosis may be correct and the issue may be completely unrelated, but doesn't hurt to mention it.