Hey guys I have a 2004 Tahoe 5.3 with 80k miles. When I start the vehicle I am hearing a loud clunk and the vehicle jerks forward. This happens about 1-2 seconds after starting. The noise seems to be coming from under the vehicle. This happens when the car is in park and has been happening cold or hot about 50% of the time. It starts fine and runs normal afterward. Any ideas? I googled this issue and couldn't find anything. Thanks for the help