[jrlrule]

Ran over what appeared to be a large rock near a construction zone and did some damage underneath the car. I can only see damage on the aluminum auto transmission oil pan. No leaks. Unsure of internal damage. Will replace asap.

But now I'm hearing this weird noise when moderately braking, shown from the video. This only happens when moderately braking. The car shifts smooth and no noticeable rattle/shaking.

I have been hearing somewhat a similar noise when braking before, but this is a lot more louder and noticeable. Brake rotors and pads altogether were last changed 20k miles ago. Is this maybe coincidental that I need to replace brake pads after this accident, or is something more mechanical is damaged with transmission (which I doubt).

Link of videos and pictures

View post on imgur.com

This is 2011 328i, N51

[marvinstockman]

Check that the rotor backing plates aren't bent.

[Serf27]

You’re missing the exhaust hanger and transmission under tray.

Noise sounds like like the rear under tray is dragging on the floor.

[jrlrule]

Thanks for the suggestions. Check the back plates and splash guard and they were fine.

But it was the heat shield between exhaust and drive shaft that got bent and shifted close enough to make contact to the drive shaft during decelerating.