Toyota Repair: viberation, drive shaft, wobbles

Question
96'4runner limited,150k,2wd,6cyl. started with a bad front u-joint , i replaced both ... still there. had the shaft bal. , then had the shaft replaced with a solid shaft (non rubber ) still viberates at speeds above 55 mph , this viberation is fast/rapid driveline vib.
local dealer says this problem is common .... starts with fr. u-joint and the viberation is coming from the trans. your in-put please !!!!
thank you  

Answer
Ive seen the tailshaft wear out from a bad u-joint.
The drive shaft wobbles and wears out the tailshaft bushing.
Grap the driveshaft yoke at the trans and see if there is a lot of play in it.
you can put a new tailshaft in it and not change the trans.

Mike