Unknown vibration source

[jamesinark]

I've posted a couple of questions previously concerning the trans yoke in my wifes '02 WS6 Tans Am and i was wondering since replacing the u-joints the vibration that I was feeling in the first place has gotten only a little better.I was wondering if worn bushings in the lower control arms could throw off the pinion angle enough to cause the vibrating?Or could the torque arm bushing is the problem?I am soon going to be converting the rear suspension to a 3-link type and putting in a watts link instead of the panhard bar it now has.I was thinking that with all the positive comments about the 3-link that along with the ability to have another way to adjust pinion angle as well as other aspects of the geometry,that the 3-link conversion would be an upgrade to the factory type suspension and its questionable geometry.Anyone have an opinion on the subject?

[HotRodKush]

When do you feel the vibrations? Does it occur while idling, under load or when moving, or all of the three? It could be a loose motor or trans mount, or a suspension bushing, or a hub bearing - really depends on under what conditions the vibration is occuring.

[jamesinark]

It occurs mainly after 45 MPH and is cyclic if you know what I mean.It also occurs under acceleration ,well I mean it actually worsens under moderate to hard acceleration and lightly under deceleration from high speed.I've come across info that may points to an output shaft bushing in the tail shaft of the 4L60E auto trans,but I'm hoping to eliminate other simpler possibilities first.

[JEFFTATE]

Sounds like a driveshaft balance or pinion angle problem ..
If the tailshaft bushing is worn , the driveshaft can vibrate..