Something hit underneath the car

[Haitham Mohamed]

I have Toyota Avensis 2008 while i'm driving, i hit something underneath the car which is high enough to hit it 

i found some scurf on the transmission as shown in the photo , i would like to know keep going and leave it alone or not

Hint

The car drives normally and there is no strange sound or anything and also this accident happened for about 2 months nearly and while i'm doing service i saw it

[TonyHSD]

Lol, that’s look bad damage outside case.
Best for your peace of mind to check gearbox oil how much inside when car is level  or drain and measure it to check the quantity is exact as the spec sheet and refill with new same type oil. Sometimes when transmission is abused a micro cracks  in the case can happen and with the time and while you are driving the car can loose oil and left dry which can lead to complete gearbox failure. The transmission oil has a very specific smell too, so after a good drive you can smell it if there are any leaks. 

[Haitham Mohamed]

Okay, i will check but it seems like no obvious leak right now as this hit happened for about two months ago, i guess if there a crack it'll be an obvious leak and i know the transmission looks that is leaking but that's an old leak from the inner cv boot