Need Serious Help!!

Ok, I have a major problem that I can't seem to solve. I have a front end clunk while turning at slow speed that has proven impossible to find, so I am hoping that somebody on here can help!!

Symptom: at low speed, while turning more than a half turn there is a clunk that is coming from what sounds like the unit bearing. It is more pronounced on the left side, and is increasingly worse under articulation, but only marginally. It sounds like someone is hitting the inside of the rim with a mallet, and can be felt in the steering. It feels almost like a binding, or like something is moving in and out of its natural seating, and makes a cracking/clunk sound.

What I have done: First I looked at and replaced all the u-joints and the balljoints. Then I looked at the trac bar, and tightened the hell out of that everywhere (currently running Kevin's conversion). After that I replaced the sway bar bushings, put all new JKS control arms in as it needed to be done anyway, with new bushings all around including the ones that are pressed into the axle. Then I checked the shock mounts, steering linkage, steering box, all checked out fine. Then I moved to the axles and had IWE inspect the rear and the front (ARB in back, Trutrac upfront) and all is good there, they think it is in the suspension.

The jeep only makes the noise when on the ground as well, as I have had it on the hoist in 4 wheel drive and tried to make the noise and it won't, even under breaking. It also only makes the noise if there is some sort of rotation/movement. If you are stationary, and move the wheels back and forth, it will not make the noise until you move forward or backwards. So the clunk is definitly load/weight related. My last guess is the unit bearings, as the sound is definitly coming from the outer axle area, almost like the lug pins are cracking within their seats, but that's not really possible.
I am running a very simple set up, ACOS up front with ZJ 5.9L springs and AAL w/shackle in the back. Only a 3" lift for now. Obviously I have spent a lot of time and money in very reputable shops looking for this problem, and have not found it yet.

Please provide any feedback you may have!!! Or if you know a really good front end place that is quite familiar with lifted vehicles, please recommend some!!! I am at a total loss. Thanx for your help.

I have this same clung appear all the time one me. It is always the tracbar mount. It needs to be REALLY tight. Also i've heard that a similar pop can occour when you have a crack in the unibody where the steering box or trackbar mount bolts. Good luck.

Something that really helped me pinpoint where it comes from was have my girlf friend sit in the drivers seat with the Jeep running and crank the wheel lock to lock a bunch of times and listen and feel everything. I couldn't really see my tracbar mount moving but when I put my hand on it I can fell it give a little.

Have you checked your universal joints in the axle shafts? If they are seized, they literally load up while turning the wheel, and then pop and rotate to relieve pressure.

Thx ukdkbr, I am going to be doing just that tonight with a friend. Hopefully this will at least pinpoint the area of the problem.

Crash, I actually replaced all of my U joints when this first started to happen, no impact at all. That was actually my first thought, as that is exactly what it sounds like. When I had the jeep up in the air, I turned the wheels to full lock both sides and watched them move under neith, and they were smooth and quiet.

Good advise though. Cheers!

ukdkbr said:

I have this same clung appear all the time one me. It is always the tracbar mount. It needs to be REALLY tight. Also i've heard that a similar pop can occour when you have a crack in the unibody where the steering box or trackbar mount bolts. Good luck.

Something that really helped me pinpoint where it comes from was have my girlf friend sit in the drivers seat with the Jeep running and crank the wheel lock to lock a bunch of times and listen and feel everything. I couldn't really see my tracbar mount moving but when I put my hand on it I can fell it give a little.

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I had this same problem. Replaced u-joints. Had a bad unit bearing, thought that was it and replaced it. It still made the noise. I then looked at the brake pads and the leading edges were gouged and worn badly. These pads were fairly new. I replaced them with some of better quality and the noise has gone.

May sound stupid, but do you happen to have a loc-right locker in the front? I have one in mine and when I make sharp turns it sounds like _hit.

Nope he has a truetrac !

happened to me, it was the trac bar relocation bracket. Took it off and made a new track bar

Hey TomH, thanx for the feedback. When I was under there looking around, I noticed the exact same thing with my brakes. So, I put a shim kit in and also laid a beed of weld down on the bottom edge and reground it to fit. Now fits perfect, but the darn noise is still there. Good call though! I keep hearing tracbar over and over again from everyone else, so when it goes back up on the hoist on tuesday, I will take that out and have a real close look at it and the mounts as well just to be sure, but I am pretty sure it is not that, as the trac bar is less than a year old, and was tightened up with an air gun everywhere about 3 weeks ago, and it is still making the damn noise. I was under there tonight with a buddy in the cab moving the steering around, and the noise does seem to be coming from that location though. Thanx for the feedback guys, all good idea's. Keep'm coming!!

Cheers!

Cheers

Well, update on the mysterious clunking noise. I ripped the entire front end apart looking for the problem, even pulled the axle. Thank god that was not the problem. As it turns out, my steering knuckle was bent somehow. I would never have noticed but when I went to re-install my caliper, I noticed that the top bolt was going in on an angle, and when I removed the caliper and looked at it, sure enough it was bent! So, I replaced the steering knuckle, and it rarely makes the noise now. I think that the remaining culprit is the brakes. The outside pad just does not want to fit flush and true, it wants to sit higher at the top, and you have to push it down, almost like it is spring loaded. I am at a loss as to why though. Maybe it is the fit of the pad. Has anyone esle run into this?? I am also using hawk performance pads with powerslot rotors. Could this possibly be the problem??

The other side still clunks as I have not taken it apart to replace the knuckle yet. It is the last thing I ever would have expected though, and I am still not 100% sure that is what it is, it could just be part of it.

Has anyone upgraded to the ZJ knuckles w/4 piston calipers and bigger rotors???

PROBLEM SOLVED! I have found the problem. It is the steering knuckles! The noise is coming from where the brake pads fit into the steering knuckle. Appearently, over time the pad mounts wear out or away at the seats they are meant to sit in and play develops. Sometimes this can be cured by adding shims, in my case not.

Solution, either lay down some weld bead along the bottom and regrind the suface back to original spec, replace your pads and hope for a better fit, or get new knuckles. I have now replaced my knuckles and the noise is gone. I have been told this problem is further enhanced if you upgrade your pads. I have been using hawk pads with powerslot rotors (which rock!!) for about two years now. Thanks again to all of you who offered your suggestions!!

Cheers!

Ok, update on this one. It is NOT the steering knuckles. Replacing them did help, but only for a short time. The noise is back and bigger than ever now. Since the last time I updated this thread, I have welded some cracks behind my steering box and tracbar mount, installed the JKS plate system for the "frame", installed all new HD currie steering, along with the steering box brace, tightened the hell out of the tracbar again, wheela alignment, inspected the front brakes. The pads are now tight in the knuckle without shims, but the clunk is still there. Lately I have also noticed a subtle clunk (same sound and area) while lightly braking at low speeds in nutral...if I hadn't already replaced my CA's with bushings, I would sware that the axle is moving front to back a bit while braking...but I dont' see how that is possible. I have ordered new bolts, sleeves, and bushings for the tracbar...maybe there is some play there. Still would love some more idea's though...

FYI, there is another thread on here with others having this problem now listed here..

http://www.naxja.org/forum/showthread.php?t=898729&highlight=brake+clunk