Out of no where the Jeep started to make a clunking noise while driving. It has about 150K miles on it. The clunk is intermittent and will do it at essentially any speed. 10 MPH to 55 MPH. You can feel it and it seems to be coming from the back. Happens on acceleration, deceleration, straight and turning.

The Jeep has been lifted 3" about 5 years ago. I used all the info from here to do it. Everything looks to be in great shape.

I read that maybe the rear upper control arm can do this and the bushings looked a little worn, so I changed it. Unfortunately absolutely no change.

It doesn't appear to be brakes related. I put the emergency brake on just enough to drag the drums and the clunking still happened. I also rode the brakes slightly and it still did it. Braking does not seem to cause it to clunk.

I had it up on the lift and can't find any thing loose, universal joints look OK, but if you guys have no other ideas I may change them.

Rear gate does not seems to be making the noise.

Any ideas.

If it is a single clunk upon deceleration and a single clunk again upon acceleration, it could be that the slip yoke splines (where the driveshaft connects to the transfer case) need some grease.

_________________
2005 KJ CRD SOLD in 2021
V6 Airbox, Samco Hoses, Provent
Weeks 1&2, Thrush Glasspack
Facet Fuel Pump, Secondary Fuel Filter
ARPs, 188 Degree Thermostat
GDE Eco Tune Full Torque
OME 1.5", JBA A-Arms and Top Plates
245/75/16s, Spidertrax

Well I replaced the u-joints and changed the fluid in the differential. The spline looked fine, but I greased it some when I put it back together. The differential also looked OK, no evidence in the oil of a problem. I replaced with Mobil 1 75W140 with limited slip friction additive.

Clunk is still very present. It is very noticeable, you can feel it coming from the rear. I put it in 4WD, no change, maybe a little worse.

However I am now wondering about the transmission, because it started making a grinding sound when I try to put it in reverse, but only sometimes. Other times it shifts normally into reverse.

Looks like I may need to take it into the Jeep mechanics unless you guys have any other ideas.

Check the Transmission mount


Sent from my iPhone using Tapatalk

Transmission mount is ok, but the transmission is not. I took it to the Jeep shot and they said the planetary gears in the transmission are "blown up". I drove it about 5 miles to the shop and I became worried it was not going to make it. Went from occasional clunk to almost constant. They are putting in a used transmission with a 12K mile warranty for $1300. Seems pretty reasonable to me. Funny how a transmission issue manifests itself as a rear end feeling clunk. I will let you know for sure after it is fixed.

Ended up having to replace the transmission and the transfer case. $2000 but she seems good as new.

Why the transfer case also?


Sent from my iPhone using Tapatalk

They said that the transmission also damaged the transfer case.

I think it was just your TC all along!

_________________
05 White Limited