NM-XJ

'98 Cherokee Sport, 4.0, Manual, Upcountry package. Exactly 100k miles. Hit some easy trails this weekend and noticed a "clunk" coming from somewhere underneath and to the front as I went over bumps. Does NOT sound like metal on metal. Think of knocking on a cardboard box or hollow wood door. Wheels straight, seems to be more on the passenger side, my brother claims he can feel it through the passenger seat floorboard. Seems more pronounced with body roll, but can't get any noise when I push/bounce the vehicle around by hand. Doesn't happen on all bumps. Checked tie rod ends, control arms, drag link, and sway bar. All nice and tight.

Any thoughts?

caged

hmm, my first thought would of been sway bar end. they tend to break at the sway bar, and pull out of the socket so to speak.

other thought would be control arm bushing.

so then i would move on to shock bushing or loose nut under the hood. maybe even bar pin.

hope you find it. those things drive me nuts too.

Jeepola

Tighten the crap out of the track bar nut on the body side. That bolt is known for getting loose, and making a popping noise. Mine did it a couple times in the past and the nut was just loose enough to let it slip and pop while turning, or going over a bump.

NM-XJ

Bar Pin?

Also, I just talked to my father - whom I got the Jeep from - and he says that a transmission mounting bolt on the crossmember is "wallered" out...but that he got "everything tightened up" years ago. Would think I could feel the trans shifting side to side via the gearshift **** if it was moving...

Hmmm. Yes, things like this drive me up the wall.

Turbo X_J

Exhaust.

unidentifiedbomb

Check your upper control arm bushings, both the arm and axle. Mine did that and I replaced the whole upper arm setup and the bump went away.

XJmike0122

I got a clunk too. I know I need ball joints. Everything but my UCA bushings have been replaced. I just passed the 100k mark. Do worn out ball joints clunk?

unidentifiedbomb

They can.

BrawnyDog

Hitting the crossmember?

Mine makes that sound when I crank.

NM-XJ

What are the symptoms of bad control arm bushings?

Edit: ie how do I diagnose when checking them?

unidentifiedbomb

A good way to know for sure is putting your jeep in reverse and rapidly hitting the brakes while knowing your control arms are torqued to spec. If there is play then chances are your bushings are bad.

steelybill

My noise was the track bar on the frame -end. I suppose it could get loose on the tie-rod end too (?)
Have someone watch the steering linkage etc while engine is running, turning the wheel from lock to lock, and maybe something will show up....

unidentifiedbomb

If it is made when turning and not moving, track bar. If it happens when going straight over bumps, control arms.

NM-XJ

So I played around in the parking lot today. Control arms are tight, and don't have any play when I back up and apply the brakes. No sound if I turn the wheels while not moving.

BUT, I have isolated the sound to large amounts of body roll/suspension travel.

Still need to check the exhaust, and also gonna check the body side of the track bar, just in case...it wouldn't happen to be conveniently hidden under the front skid plate would it?

NM-XJ

I think I've isolated the source of the clunk. NOT the front end. Seems to be the slip yoke and transmission/transfer case. The Slip Yoke has about 1/8" play at the U-joint, and the transmission/transfer case starts clunking if I really get things moving around...

https://www.youtube.com/watch?v=vhA3...ature=youtu.be