How can I tell if I cracked my differential on my AWD sedan?.

 

It would be leaking fluid through the crack.

 

Where would have leaked? Onto the floor?. Would the leak be visible?.

 

I was testing my AWD brcause it's been acting really weird lately.. Like it does burnouts(wtf) so to test it I gas/braked and it bunnyhopped and I heard like a pop

 

sound come from the front or the back differential?

not normal to have problems with the diffs - especially at the stock HP.

If you can drive and it doesn't make loud terrible sounds then your differentials should be ok.