Strange clunk after 3.5" lift

[1988MJeliminator]

Hello,

I have a 1988 eliminator 2wd and I just recently put on 3.5" lift and right after installation I have noticed a loud clunk under the driver and passenger floor boards.

All the parts I used:
Rubicon express 3.5" front coils
JKS UCA
JKS LCA
JKS adjustable Track-bar
JKS adjustable sway bar links
Bilstien 5100

Right after finishing putting the lift on I drove it around the block and discovered a new loud clunk that I can feel under my feet while I drive. I checked everything for movement or rubbing and the only thing that I found that seems to have play is where the LCA meet the unibody frame. I re-checked the torque specs for what the bolt should be tightened on the LCA but all my bolts were all torqued. The clunk is really loud when going over little bumps in the road but its goes away when your on the freeway. there are still minor clunk noise on the freeway but you can't really notice it. Also when I brake over little bumps the clunk goes away.

I was just wondering if anyone has had this problem before or if anyone has advise that will help me solve this irritating clunk. The truck is used as my DD and I have learned to live with it but it is definitely annoying when your on a really bumpy road.

Thanks.

 

[Tim_MN]

..... the only thing that I found that seems to have play is where the LCA meet the unibody frame......

Fully describe what this means, and if possible post a picture showing where this occurs.

If the lift was correctly installed, there should be no clunking.

 

[Johnnie Walker]

Did you make sure the Jam nuts for the CA's were tight? Any slop in the CA joints?

 

[trippled]

Sounds like bad control arm bushings or loose control arms.

 

[1988MJeliminator]

Fully describe what this means, and if possible post a picture showing where this occurs.

If the lift was correctly installed, there should be no clunking.

What I mean is that there is two connecting points to the LCA. The one bushing is connected to the front axel and the other bushing is connected to the frame. the bushing that is connected to the frame seems to have a little movement when you move the tire back and forth.

hopefully that makes sense if not I will try and attach a photo.

Thanks for your help.

 

[blondejoncherokee]

post pics.
there are tons of things that could cause this.
if your frame side LCA bushings are bad that would cause a clunk. wallowed out LCA holes with bolts not torqued can do it, bad TREs, loose trackbar or mount, loose UCAs, etc

make sure everything is tight. like double and triple check each bolt.
could be a bad tranny mount or a bad U joint too.

 

[cdn_xj]

Check your trackbar mounting bolts, in particular the frame-side mount. The trackbar has to contend with a LOT of forces. So much so that even though the mount seems tight it can still shift and clunk.

I was chasing a clunk in the steering for months before i finally figured it out.

 

[bentroia]

After installing JKS lower arms on my 97 XJ with a similar lift height. It made a clunking noise that was difficult to identify. After checking and re-checking everything many times... I figured out that it was the JKS control arms. Rolling slowly over a bumpy service a buddy wrapped his hand around the JKS arm and figured it out... The threaded interface between the arm sections had enough play to make noise/knock in a vehicle that was otherwise in very good condition and quiet.

I was in denial thinking it could not be the arms, then I tested with the old arms and the noise went away... SO... I replaced with Metal cloak arms and the the problem is gone...