When decelerating there is a knocking sound from the center bearing area. The center bearing and rubber were replaced three months ago so I rule that out. Under load the shaft is quite. When the foot comes up it's knoka, knoka, knoka. At drive shaft speed and more noticable at lower speeds like comming to a stop. Not the sound a bad pinion would make either. Could this be the universal joint? How much slack would there have to be to make this noise. Would the slack be visable where the shaft enters the bearing cup? How do you test a universal joint?
Edit: the flex disks were replaced along with the center bearing. There is a vibration damper in the front. All the bolts are tight.

__________________
1984 300SD turbo 126
"My true love"

God made me an atheist and who am I to question His wisdom