I feel like this might be kind of a dumb question, but I'm installing the Bilsteins on the front end of my truck. Do I need to use the washer & nut that came with the Bilsteins for the top of the shock, or was I supposed to use the existing nut that came off of the factory shock? The reason I ask is the factory nut has a washer with a much larger diameter than the one that came with the new shocks. But I could not get that nut all the way down. It started fine, but became extremely hard to turn. Thanks for the help.