JKcity

It is as bone stock as it gets, just like it left the factory. Bracket hitting a frame though is a good description of the sound. A shift and decent tap type noise.

And of course there is the random factor, last night it is doing it every stop and coast/start. This morning for 1/2 hour drive nothing until very end when I am pulling back in home. If I had to say it seems to rarely if ever to be there in first 15 minutes of drive which of course had me thinking of heat related. Could that be a bushing getting warmer near exhaust, diff warming up, who knows.

I get these are tough which is why again I have a warranty!

Rednroll

With problems which are intermittent or difficult to reproduce and diagnose, the best method I've found is to pull out a camera and video tape the problem. It serves 2 purposes. It provides the techs doing the analysis some insight to reproduce and diagnose, it shows undeniable evidence of the actual problem. So if you really want to have the dealer fix this under warranty, that will be your best course of action.

JKcity

Yes, I will strap my camera under there soon enough. It is faint enough I am not sure the sound would get picked up in the cabin. And it's not that difficult to produce, the tech heard it multiple times and acknowledged it while riding. Hence why when we got back he tried tightening the LCA bolts after he acknowledged he never left the parking lot on his test drive. What I need is one who does not say it is nothing to worry about "at this time", per the service invoice.

resharp001

I'd be frustrated if I was in your situation, or many others for various reasons. Honestly, these are the best vehicles, and the worst at the same time.

JKcity

I found some youtube video that are very similair and were transmission mount. The clunk happens just after you start moving, not right at start. I think I read in past you can move mount a bit and stop something from hitting, worth a look when I get time this week at least in addition to bolt torques.

resharp001

Seems like I do recall some troubleshooting with tranny mounts on other threads. I'd think that would be more distinctly sound from under you more than the rear, but I know it's hard to pinpoint sounds from inside. That makes sense in that you'd feel it...although would seem odd on a jeep not very old at all. Curious to see......please update when you have time to look at it.

jburasco

So the dealer recommended I have my fluids changed in my differential last week when I went in for my oil change (just under 36,000) and now i keep hearing this clunk coming from the rear end when the weight shifts from a stop. Concerned. Would this still be covered under my powertrain warranty?

resharp001

Sounds typically take some troubleshooting. Profile details are scarce. Is your jeep modified or stock? I'm going to guess that this is just coincidence in timing with your service. They just drained and refilled your gear oil (my understanding) and wouldn't have touched anything that would have started making a noise. Flat surface, you get a clunk when weight shifts forward/backward, like when coming to a stop or accelerating from a stop? That symptom typically points to an under-torqued control arm bolt.

Sometimes rear end noises can be duplicated by just putting two hands on the rear side of the jeep and just getting it rocking back and forth to see if you can recreate sounds. You could even do the same from behind pushing it forward and letting it rock back.

jburasco

Stock. It can be from flat and happens as I accelerate, but not always. Tried in parking lots yesterday. But for example this morning...Slight incline backing out of my garage this morning and as I headed up incline you just hear a clunk.

resharp001

Something that you can reproduce semi-regularly? Single clunk when it happens? Nothing rotational right....nothing that keeps happening and changes with speed? tires been off recently? Did the dealer perhaps rotate em? Might double check torque on the lug nuts if so. This primarily sounds like a loose bolt/nut to me.