What happens when the transaxle on 2006 Pontiac torrent acts up?

You sound like your dragging a muffler (lots of metal on metal sounds) - pulls when brakes - vibrates in floor/pedals and steering wheel - when turning there is clicking and knocking sounds. All of these symtpoms can be varied in degree of severity and frequency. If you can push your vehicle forwards or backwards when in park and it moves more than the standard couple inches then your chain has been stretched and chances are the gears have been chewing each other up. Worst case scenario has been described as a loud cracking sound (that is your transaxle giving) and loss of acceloration power. You will still have steering and brakes but it is advised that the vehicle not be driven on the highway.