Front end popping noises

Hello guys,
Since mid-summer I have been chasing done front suspension issues associated with my cherokee.
1. 1988
2. 4.0 I-6
3.Auto - AW4
4.D30
Recent work:
Replaced all balljoints and TRE's, and upper control arm bushings. After replacing all the above parts a loud popping noise still persisted while driving. On the Jeep I have adjustable UCA's, Drop pitman arm from MJ, ~3.5" Lift. I believe that this problem may be due to a worn out adjustable track bar, although I had just replaced the TRE on it. Can the Bar it self be worn out?

is it when taking off or right after stopping? The older brakes can develop an edge on the caliper bracket that can and will catch. Basically just wears out and make a grove..

Front axle popping is most often associated with the track bar.

Inspect the lower bushing and axle mount for wear or damage. Often the bolt hole on the axle bracket will open up and the bolt clunks. Inspect the upper joint and frame bracket for wear or damage. Failure of the joint is not always obvious. The bracket can wiggle around on the frame even though the bolts are tight. A slight movement of the bracket allows it to slowly grind the bolt holes larger and the bolts themselves get
smaller. Movement at the frame bracket will often creak slightly at first, or will clunk as wear accelerates.

How do you motor mounts look? Does it do it all the time? Only big bumps? Around corners? Every pebble you drive over? Haha, sorry for all the ???

I had a clunk on mine after replacing bushings and ends, ended up being a motor mount, on big bumps or pot holes on road, off-road or hard acceleration it would do it.

My motor mounts are fine, replaced withing 20k; will double check though.
The clunking happens either when going fast or slow. Seems to do with the trackbar because the most violate clunks result when going over a bump with the steering wheel turned. I will check the frame mount associated with the TB.

It'd be worth checking the sway bar bushings too while you're under there

You said you have adjustable UCAs and an adjustable track bar. You really should have included details about these parts. For your symptom that data would add a lot.
Have a look here:
http://www.naxja.org/forum/showthread.php?t=1069576

Lots of similar symptom and causes.

bushings and loose bolts

More than likely a crack. When I had a chance last week I was able to clean off the frame and saw what looked like a scratch mark. Due to rain and limited available time I wasn't able to investigate further.

Ok. Where?

I also have a loud popping noise, and isolated it to the last 1/4 turn hard left. I've changed the track bar, TRE's ok, bushings fair, but when you touch the steering box, you can feel it. Can't feel it on the steering shaft or drag links, tho. Leaning over the fender, you can feel it thru the sheet metal. You can definitely hear it near the box.

I'm thinking the chassis at the steering box bolts has cracked, I've seen pics of it before. At hard left the box is getting shoved into the unibody with a lot of pressure. It's pulled away hard right and won't.

Is that anything like what you have? Left or right can make a difference.

What size tires? I went to 245x16's, 215k miles. Folks wheeling bigger have noticed it pretty early in their off roading. Jeep unibodies are notorious for flex cracking. The silver lining is that winch bumper reinforcement plates help fix it, what a great excuse.

Not to mention it might just be the aluminum spacer underneath.

My 94 popped when turning, it had a simple 4" lift. Turned out to be the sway bar. I removed it, no more pop and it drove fine with out it.

The popping noise has been determined to be my adjustable track bar hitting my differential. The point of contact on the TB is where the tierod end threads into the TB.
Recently I went back to some LCAs from IRonman, turns out he made them way too long for my specs; thus allowing the differential to be hit by the trackbar. I am swapping out those control arms for some shorter ones that would fit more appropriately.

Thanks for posting the result!

So I can fully confirm that the issue was related to the lock bolt on my adjustable TB contacting my differential cover.
The solution was to remove both wheels, detach TB, unbolt shocks, and use a pry-bar to pull the axle towards the steering wheel. Test drove the girl and took some speed bumps at high speed and there was no bump.