"Talk-to-text"? So, what you've got there is when you use the microphone while texting an SMS, it censors inappropriate language. When you use the keyboard, it is not censored. I can guess this, because I just tested it both ways, and it does indeed censor it on my L635 if using speech-to-text to enter the message.
There is no way to disable it, as far as I am aware, or in any way that I have been able to locate thus far. Perhaps another user will see this and be of more help. I responded in order for people to understand how to duplicate your issue, so they can help you to resolve it. I'm at a loss.