I have an 88 Bronco and love it. I recently put a rough country 6 inch lift on it but have not changed tires out yet for bigger ones. After the lift I have noticed a vibration/shake between 15-30mph and when coming to a stop. It doesn't do it if i put the truck into neautral when coming to a stop. I have greased the slip joint, and the u joints don't look bad. After greasing the slip joint it seems to have helped with the vibration between 15-30 a little but nothing on the stopping part. I looked to make sure I put the rear shims in correctly for the angle of the rearend to the driveshaft and the blocks I put in don't look to have any angle in them. Not sure what it means when there are no problems with the truck in neautral. Thanks in advace for the help.