XJ Drivers side clunk - Looking for answers

Well, I've searched and tried everything that I can and no luck. Took it to a mechanic friend today who is a MB tech - so not a ton of jeep experience - and he couldn't track it down either (but definitely felt it).

The noise is felt mainly by my foot on the drivers floorboard, and can be heard. It is a hollow clunk that can be reproduced easily by turning left over bumps (when the drivers front tire is slightly unloaded), though it can be felt going straight as well. Not evident on the right side. A washboard surface really brings it out. Not felt through steering wheel.

Background - Prior to lifting the jeep it rode well with no odd noises. Installed lift approximately 1 year ago and have been trying to deal with this ever since.

Lift (DPE hybrid OME 3") -

• OME 2" coils w/ 1" spacer
• OME 3" leafs w/ rubber oem bushings
• OME nitrocharger Sport shocks (standard length)
• JKS LCA's
• new OEM UCA's with new WJ bushings on Axle
• JKS adjustable track bar
• JKS quick disconnects
• New crown heavy duty steering (ZJ) w/ OME stabilizer (garbage - should have just bought the Currie stuff)
• Hack 'n tap & new rear driveshaft

Since then, I've done the following to try to solve the clunk...

• new trans mount
• sway bar bushings
• c-rok steering box reinforcement / steering box
• axle u-joints
• ball joints
• unit bearings

I've driven without the front driveshaft, without the sway bar entirely and still have the clunk. I've had the tires roadforce rebalanced and rotated.

I have spent a ton of time on this thing (and money obviously) and can't believe I can't find this $&#$ clunk. I'll buy anyone dinner if they can help me solve this...:dunno:

my vote is for a control arm bushing that is either loose, or cracked.

I had the same problem and solved it by ditching me RE CA's and going ROKMEN dual Johnny Joints.

double post

i would have someone turn the wheel while you are under it feeling things for clunks. could be a trackbar bushing, control arm bushing, tie rod end, bad shock bushing etc. just have to start inspecting things

Yeah, did that today and can't duplicate anything while standing still. Jouncing it, or turning the wheel.

double post

i had exactly the same problem as you, and have almost exactly the same parts set-up on my '01, except i have different brand shocks and the Currie steering set-up (yes, the Currie is great stuff). anywho my clunk was on the passenger side, thru the floorboard, yada yada, exactly as you describe. you will probably notice that if you apply light brake pressure the clunk will stop? good indication it is an LCA/UCA. i spent many months swapping mounting hardware, replaced the unit hub, tightened the heck outta everything, etc. in my case it was something internal with the JKS LCA (the bushings were good, no visible sign of a problem). the clunk would stop if i packed the LCA with grease, but would come back in a day or two. long story short, i replaced the LCA with a new one from JKS and the problem went away. weird thing is the LCA looked/felt fine off the jeep, but clunked like crazy when installed...go figure. anyway, hth.

did you retorque all of the bolts in the suspension after a few miles after install?

my vote goes to control arm bushing, or a wallowed out mount in the frame. You used the factory bolts and didn't substitute any SAE ones for replacements?

87manche said:

did you retorque all of the bolts in the suspension after a few miles after install?

my vote goes to control arm bushing, or a wallowed out mount in the frame. You used the factory bolts and didn't substitute any SAE ones for replacements?

Click to expand...

Yeah, I've retorqued everything periodically. I replaced most hardware with the same spec metric oem bolts. Maybe track bar axle end, but I see no bolt head movement evidence and the bolt is tight.

Otter said:

i had exactly the same problem as you, and have almost exactly the same parts set-up on my '01, except i have different brand shocks and the Currie steering set-up (yes, the Currie is great stuff). anywho my clunk was on the passenger side, thru the floorboard, yada yada, exactly as you describe. you will probably notice that if you apply light brake pressure the clunk will stop? good indication it is an LCA/UCA. i spent many months swapping mounting hardware, replaced the unit hub, tightened the heck outta everything, etc. in my case it was something internal with the JKS LCA (the bushings were good, no visible sign of a problem). the clunk would stop if i packed the LCA with grease, but would come back in a day or two. long story short, i replaced the LCA with a new one from JKS and the problem went away. weird thing is the LCA looked/felt fine off the jeep, but clunked like crazy when installed...go figure. anyway, hth.

Click to expand...

Well, I will give this a try. The grease prevented whatever it was from banging around apparently? My mechanic friend wondered if it could be something internal on it...

Did JKS back this and send you a new one?

I would bet something with the track bar. Did you change the frame side track bar mount with that JKS bar?

jdbwrx said:

I would bet something with the track bar. Did you change the frame side track bar mount with that JKS bar?

Click to expand...

Frame side mount is stock except for drilling out the hole and inserting a tapered sleeve.

Check the torque on the steering box bolts and frameside trackbar bracket, also check that frame area for any cracks/movement/slop. I went thru the same thing a few weeks ago. The bolts werent loose, but only snug, but not snug enough that stuff couldnt move. A couple of the bolts took a ~1/2 turn until they were properly tight again and the popping disappeared.

"Did JKS back this and send you a new one?"

No unfortunately. However, he did examine the LCA and found (according to his measurements) that there was no excessive play/slop. thing is the new LCA stopped the clunk and has been fine for years since. btw i did also swap in larger mount bolts and retorqued many times. by no means am i trying to bag on JKS - they make great products imo. just in this case the issue was a bit...eh, mysterious.

I noticed a new symptom today when braking very hard. I get a grinding that sounds similar to tire rub on a flare (but that isn't it). Only from drivers side.

Control arm? Upper or Lower a good place to start? I'm hoping that this noise is related to the issue I originally posted. I'm starting to suspect the upper control arm frame side bushing...

Just throwing this out there, but is everything in your braking system tight? If the caliper is loose, that might cause a clunk, and certainly could produce a different grinding noise under braking.

Thought I'd bring this back from the dead...

I finally solved my problem with the rattle. It was the lower coil spring retaining clip on the driver's side. The clip was about 1/2" away from making contact with the coil. So, when the driver's side was unloaded during a left turn, and I hit a bump, it was really noticeable and felt "loose".

Thanks to everyone for the suggestions. I'm just glad I finally found it!