driveline vibration
 

I have a faint vibration in the rear of my car, 05 magnum r/t that comes on at about 50 mph. I have two sets of wheels and tires, and have re-balanced both sets to no avail. Next logical thing seems to be driveshaft/drive train.

I have been suspect of the driveshaft coupler bushings, so finally tore it apart today. Do these bad enough that they could be causing a problem? They are a little cracked, but the integrity of them seems intact.

I also intend to replace the driveshaft carrier bearing.

Questions I have...

Do those rubber couplers go bad ? How many yr's or miles is typical ? I have poked around a few forums and found guys that wrecked them with big HP, but that isn't me.

Can the actual u joint be replaced on this shaft ? I have read it is not serviceable ?

Given the intensive labor required to do all of this, i am looking to upgrade to something that isn't going to cause problems in 20k miles. Anyone have any recommendations for a center bearing ? I have only been able to find a $80 autozone one that is probably garbage. Do aftermarket coupler bushings exist ?

Any experience or thoughts you can share are appreciated.