Driveline \"clunk\" question. need help! I am in the process of replacing my transmission mount in the morning. I got the mount today and am ready to install. I have another problem I have discovered. When I put my K5 in park on a hill, it will not stay put! It shutters the gear and skips and rolls away. It is like it is trying to catch and can't. It will skip then roll, skip then roll. This is in park with the engine off. I have a good emergency brake thank goodness, but I want park to be PARKED!! help! Also, could this be in the gear select on the column linkage? At times the linkage tries to not let me take the key out of the ignition unless it is jammed up into park real well. A common GM problem in linkage, but I've never seen a truck try to roll!