Drive shaft vibration

I have a drive shaft vibration in the 40-50mph area. I've had it since the truck was new, it was very minor then, and of coarse the dealership never found it. Lately, with more miles on the truck, it got a little worse so I had the drive shaft rebuilt and balanced. I still have it but it is a little better. I suspect it's the transmission tail extension bushing. Can this be replaced without taking the trans a part? It would be a big job if you have to disassemble the trans.

 

Sorry I forgot to add type of trans. It's a 2002 S-Runner which has a manual 5-speed.

If I grab the yoke and try to move it up and down I can feel it move in the bushing. The Toyota dealer said they have to take the trans apart to change the bushing. $$$$

Toyota told a trans guy there is no bushing. I was looking at the service manual and it's hard to see hoe the yoke is supported in the drawings in the manual. I should have looked in the output shaft hole while I had the driveshaft out.