This is driving me nuts. I have an 05 Tj with 3 inch lift transfer case dropped about an inch and cambolts I still have a vibe at about 40 to 50 mph i looked at my shaft it has a huge round thing that looks like some type of balancer are these known to go bad? can they be removed ? any help would be great

Vibrations can be caused by many things to say the least. I think you are probably on the right track with the driveshaft.

Crawl under and grab the driveshaft. Shake it, sometimes bolts backout and come loose, could also be a bad ujoint. The tranfercase drop kit helps your angles but when you think about it. You added 3inches of lift and only 1 inch of drop. That is still a 2 inch gain in angle. Which increases the wear of the ujoints.

I would bet you have a worn ujoint.

Now, if the steering wheel shakes a bit then you might also checkout all of the TRE's and ball joints in the front as well as problems with the tires.

We need a little more information..... did the vibes start with the lift, or later? Vibes felt in steering wheel or seat? Do you have the 4.0L or the 4 cylinder? I assume no SYE. Do you have a front locker? If NO FRONT LOCKER, have you tried removing the rear DS and then driving the Jeep in 4wd HI? (Don't attempt this if you have a non selectable locker in front). Did the vibes go away?

you have a rubicon I 'm guessing since you said there was a balancer on the shaft, you need to change the flange style yoke on the case to a yoke style and run a cv shaft. its not too expensive to do. let me know if you need some help.

We like to keep the factory flange on the ruby's and run a 1350 c/v shaft - the yoke is a smaller than stock U joint 1310 usually , But the 1310 is cheaper if that's what your after -Jess