That slapping noise you heard most likely was due to the driveshaft hitting the exhaust heatshield due to the center bearing being shot. The same thing occurred on mine before I replaced the bearing. It was a loud grinding sound.

If the shaft is out of balance that could cause shaking too, among other things, such as failing rear suspension parts. Does the shake vary with the speed of the driveshaft?

Quote Originally Posted by Hypr5
When the shaking first started happening, while reversing i heard a noise that sounded like metal slapping metal. It has since gone away and I am left with only shakes. Would that be the type of noise or would it be more of a groaning?