I recently replaced all 3 U-joints and carrier bearing in my 2001 Silverado 2500HD diesel truck which has the 2 piece driveshaft. I marked all mating surfaces with some marking paint to make sure the installation was correct so the shaft would be in balance with the truck before I removed the driveshaft. The installation was the same and everything lined up perfectly. I took her out for a spin and no vibration through the rpm range, she felt nice and smooth. However, I was decellerating down a low grade and I felt a shutter under my feet which I would guess was where the drive shaft inserted into the transmission. I drove around and went down a few more hills. The shuttering seemed to reduce each time I decelerated and hit the brakes. I did this about 6 or 7 times and now it is gone. Has anyone here had this happen to them? I"m a little concerned but not sure if I should be or not????