Chevrolet Beretta "Workshop Manual" request

I have a Chevrolet Beretta GT, the car works very well if it were not for some pulls that are undoubtedly the box, automatic, and seen the options and they tell me that it can be the filter of the box, I want more opinions, the car is walking as much and suddenly paste pulls and the revolutions fall. I would also like to have a mechanic manual to make the maintenance. Anyone who can help me would be eternally grateful.