I am stumped on this one. I have a 95 Stock XJ 5 speed 4x4, 2.5l with 204K.

Here are the symtoms:
I noticed that it started having this weird slight/shake vibration. You notice it on the highway and the rear view mirror vibrates so the cars behind look they are bouncing around. If i have something in the passenger seat, i can also see it vibrating. I don't really feel it in the steering wheel at all. Sometimes it is really noticable and other times it is not that noticeable others. Usually happens around 55mph and up, but sometimes i notice it around 35mph. Does not do it when car it sitting still and i rev the engine.

Here is what i have tried:

-rotated and balanced tires, then swapped the tires and wheels for a completely different set
-replace front and rear driveshaft u-joints, balanced both driveshafts
- replace motor mounts and trans mount
-replaced all 4 shocks and track bar
-checked both pinion bearings, they look good
-ball joints, and tie rods look tight, steering is tight
-wheel bearings and front axle u- joints were replaced about 1 year ago

Does anybody know what this is? This is drving me crazy not be able to figure it out. If you can find out what it is and it fixes it, i will seriously send you $20 via paypal for the help. that is how frustrated i am.



Thanks guys

 

You have axle shaft u-joints. Check for play.

Buy yourself $20 in beer and tell me how you like it.

 

Have u checked the ball joints? Also how are the rear bearings?