Cherokee newbie here but not a newbie to 4x4's. I am looking at buying a 97 GC that has a 4" lift and new 32" radial MT tires, the rig is fairly clean and the lift was professionally installed according to the current owner. The problem is it has a vibration on the road that feels like a u-joint but all joints appear tight and the current owner says he had a mechanic check it out mechanic says all u-joints are good and that the problem is the upper control arm bushings are bad and that is causing the vibration. Is it possible for those bushings to cause continuous vibration like that?
Thanks in advance and sorry for the long post.

 

What kind of vibration? Front end shimmy? Bump steer? Death wobble? Rear driveshaft vibes? Etc

 

It feels like a rear drive shaft vibe but I feel it in the steering wheel. He had the stock full time transfer case replaced with a NP 231 and now it has 2H, 4H, and 4Low. if you put it in 4H the vibe goes away.

 

I had a tire get bad from my driving. And I was searching tie rod ends, sway bar, barrings and it was a tire in the end

 

Put it in 4wd and it goes away, sounds like U joints. Feel it in the steering wheel sounds like any tie rod end, track bar, ball joints...jack it up and put a crow bar under the wheel and check the ball joints with a good flashlight as you lift up and down, then check all the tre's ...All of them...as someone turns the wheel with the front end on the ground. Look for play on the passenger side of the track bar
I would suspect U joints if all of that is negative

 

Check the front differential's internals. Being in 2wd now, the front wheels are turning the ring and pinion on the deceleration side (backlash) instead of the powered driving side. Back in 4wd, the engine is driving the gears in the normal direction.

Boy, that took a lot of brain drain it think of that! LOL!

Actually my WJ blew it's rear axle last December while in 2wd where it usually runs and the t/case got kicked out of gear. After replacing the axle, I can't get the t/case to go back into 2wd, so I've been driving it in 4wd full time since then. I got worried about the condition of the front diff so I pulled the cover and looked it over. I noticed the decel side of the ring gear was shiny because most of the time it's been in 2wd. That's with 235K miles in it.