[syzygy]

I've got the same issue on my TH (3/15 build date). I've posted in that other thread you linked to, but it would be nice to start one dedicated to this. I plan on waiting until my first dealer oil change and see what they say. The sound (to me) is more annoying than worrisome.



Here's my take on it:
It sound and feels like a weak rumble strip. It is barley noticeable on coarse pavement as it is drowned out by tire noise. Above about 40 mph it is either gone or covered up by other noises. It does not matter if I've been driving for 5 minutes or 5 hours.


I can switch it on/off at will. It's only present in auto-shift and auto-4wd. If I lock 4wd or change to manual shift mode it goes away completely, or will never occur if left in those modes. If I leave it in auto and keep a steady throttle at 25-35 mph the noise/vibration will "switch on" after about 10 seconds. I'm sure I could time it's start with a stopwatch as it seems 100% repeatable on my normally traveled routes.


If it's making the noise/vibration, it will switch off if I either: shift to the manual-mode transmission gate, or lock the 4wd. Within 10 seconds of switching either back to auto the noise/vibration returns. Like clockwork - it switches on and off very abruptly. It is definitely something in the system switching something on/off.

If it is missing in 4 lock it may be something to do with the rear axle disconnect. A grinding noise can never be good.

 

[syzygy]

My noise could never be described as "grinding". That's why I feel okay waiting it out until it's broken, or I take it in for an oil change.


Why, would you guess, it goes away in manual shift mode? Is 4wd locked in manual shift mode too?

The op said it was not present in 4 lock.

 

[syzygy]

I just took it for a quick drive... it's very difficult to describe a sound ... it's more like rumble strips than a 'grind' sound, but you can feel it. My sound/rumble does not go away when I put the shifter into manual mode or into neutral.

You said "The noise does seems to go away when switched into 4WD Lock."

 

[syzygy]

That's correct, the sound subsides when switching into 4wd Lock.

Then perhaps it is something to do with the rear axle disconnect mechanism.

 

[syzygy]

Ask your dealer to give you a letter saying it is normal. If they wont do it ask why not.

 

[syzygy]

The post made by Tony above is in reference to my Jeep. After 3 dealership trips, they are still at a loss as to what is causing the rumbling noise when I let off the gas or coast between 20-40mph.

It sounds like someone downshifted one too many and it almost resembles that rumbling sound. I've tried forcing the 4wd lock on when it makes the noise, I've pushed it into the "manual" mode as well as turning the traction control button off. All of these make the noise stop immediately but it just comes back the next day.

If anyone has any updates that would be fantastic. Chrysler/Jeep is now filing this away as normal.

Why did he post for you?

 

[syzygy]

Well i hope they come up with a fix soon, the noise is getting worse, which doesn't give me the warm fuzzies that associated wear is going to be minor.

is there a youtube or other recording of the noise.
My trailhawk does not seem to have it at 800 miles.
People often moan about my ability to hear every noise.

 

[syzygy]

mine made a funny noise yesterday when decelerating at about 30mph. It was more of a droning noise which I have not heard before.
I was however approaching a roundabout I have not yet driven in the Renegade. It may have been a road surface issue.

 

[syzygy]

Okay, all, I finally have an update on this!

Per our engineers, the required repair for this is a replacement of the Rear Differential Module (RDM). It is a hardware replacement, not a software update. It is available now, but it will take some time for parts to reach dealerships and should be more widely available early next year.

This is information that is just newly being released, so please be aware that not all dealerships will be immediately aware that the fix is actually available. If they have any questions regarding the repair, our engineers should be able to assist in answering their questions if they reach out to them directly.

I'm excited about this one, I know it's been a long time coming for some of you and I've been anxiously awaiting a resolution to this myself!

sorry, but I am far from exited about this.
My car may need a new rear differential?

 

[syzygy]

Sorry for any confusion, it's the rear differential module that needs replacement, not the full rear differential. My excitement was more for the fact that a repair has been announced, not the repair itself; I was happy to finally have solid information to be able to give you guys.

yes, sorry I read that but someone said they had there rear diff and drive shafts replaced.
I feel better now.
I am not sure mine does it anyway. I have heard an occasional sound when slowing but certainly not all the time.