I changed my open 2.79 8" rear pumpkin to a 3.55 traction-lok rear and now have a vibration which is really noticeable. It is steady during driving and really gets bad when I let off the accelerator. I didn't change anything else except axle seals so it has got to be something with the pumpkin. My first inclination was to make sure that the u-joint was put in correctly between the "knocks" when it was reinstalled, and that is ok. I got the pumpkin from a friend who had it in his car for about 3 months and then took it out when selling the car. He says it had no problems in his car. Everything went back together perfectly with no problems, so any ideas?