The AA flight will arrive into T3 at GRU. There is a transfer security that you could access, but they will want to see a boarding pass. The TAM flights will depart from T1 or T2. It's about a 15 minute walk .

I don't recall seeing transfer desks at T3, but AA might be able to issue you your boarding pass in DFW. But that will bring attention to the fact that you are violating the MCT. AA>JJ I-I MCT at GRU is 1:15.

Seems like a dicey connection. Might want to look into a GRU-EZE flight or later GRU-AEP.