I just installed the Lorenz Billstien 5100 series kit on my 2500 diesel.( 2008 ). Everything is good except at speeds greater than 40mph if I hit an expansion joint, or a good size bump, the truck shakes wildly. This has never happened before the kit was installed. I got the IR plush coils and the dual purpose leafs with the kit. Anyone having problems with this severe shaking, and how did you fix it? Do I need a drop pitman arm????