My Silverado is starting to make me nervous. When coming to a stop, after I apply the brake, the transmission will sometimes make a clunking noise. It has also lunged forward on me before and taken me by surprise. It has no problem shifting up through the gears. I can punch it and she'll go just fine. However when I start to brake that's when it starts to make a noise when it shifts down. Usually only shifting from 3rd down to 2nd, and then 2nd to 1st. I only notice it when driving in the city. Never on the interstate, where it can stay in higher gears. If anyone has had this issue, which it looks like it may be a common one, will you please get back to me and tell me your solution. Thanks in advance.