New owner of a KK (2012) - thumping noise

phrogg108 · **Posted:** Tue Nov 22, 2016 11:37 am

Hi all. I am a new owner of a 2012 Liberty Sport. Please be gentle.

I bought it from a private seller about two months ago. 61k miles on it. I have searched through the forums for my issue and have found a few things here and there, but wanted to make sure I am on the right track.

There is this infuriating thumping that comes from what feels like the center-ish/passenger side of my Liberty. It seems to be very random, happens mostly in 2WD but has now started a little when I switch to 4WD. It does not seem to be suspension related: i.e., it does not always happen, it does not happen over bumps, it happens on flat surfaces, etc. It can start anytime and go away any time. I hear/feel it when I pull out of the driveway some days and not other days. I hear it when I slow down sometimes and not other times. I hear it when I am going a higher speeds and not other times. Hence the "infuriating" adjective.

I see posts/threads about CV joints and replacing driveshafts/axle shafts, but I am trying to put this all together to see if I can figure out what is really going on.

Where do I start? What do I look at?

I have always had Mopars of some sort or another and this is my third Jeep, but this is a noise I have never heard or dealt with before. I am sort of at a loss and would love some kind of help, input, direction, etc. If there is another thread referencing all of this, please point me to it! I tried to find it before I posted this, but got a bit overwhelmed. I am hoping all you experts can assist.

Thanks in advance for any advice, assistance or other suggestions.

Scar0 · **Posted:** Wed Nov 23, 2016 11:51 am

Check the front CV on the front drive shaft at the X-fer case. You should have little to no play in it, and the rubber boot should not be torn. Also no grease splatter visible in that area.

phrogg108 · **Posted:** Wed Nov 23, 2016 11:59 am

Thanks. We will be looking into all this over the coming weekend. The noise has gotten a LOT worse lately and it is driving me crazy. Is this the whole "replace the CV joint and intermediate shaft" bit? I have found references to that in this and other forums....

tommudd · **Posted:** Wed Nov 23, 2016 4:10 pm

phrogg108 wrote:

Thanks. We will be looking into all this over the coming weekend. The noise has gotten a LOT worse lately and it is driving me crazy. Is this the whole "replace the CV joint and intermediate shaft" bit? I have found references to that in this and other forums....

No the CV and intermediate shaft is part of the drive train from the diff to the wheel ( right side)
What he is mentioning above is the front driveshaft

phrogg108 · **Posted:** Wed Nov 23, 2016 4:14 pm

[/quote]
No the CV and intermediate shaft is part of the drive train from the diff to the wheel ( right side)
What he is mentioning above is the front driveshaft[/quote]

Ohhhh... is there a way to tell which one of these two things is my issue? Or is it just a matter of taking both things apart?

Scar0 · **Posted:** Thu Nov 24, 2016 2:51 am

A good X-fer case CV should look like this.

lfhoward · **Posted:** Thu Nov 24, 2016 9:11 am

There are some helpful pictures of bad ones in this thread, along with replacement instructions:
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=16&t=56917

phrogg108 · **Posted:** Thu Nov 24, 2016 8:21 pm

Thank you all!! I'll check these things out this weekend!!

phrogg108 · **Posted:** Mon Nov 28, 2016 10:24 am

New noise started this weekend: when I have the car in 4 wheel drive (because the thumping noise is a lot less obvious in 4WD) and turn left, it makes a HORRIBLE sounding noise. I assume that is the CV joint? My husband seemed to think it is, but I figure I ought to ask all you experts too.

lfhoward · **Posted:** Mon Nov 28, 2016 12:36 pm

Hello,
Just checking: does your 4WD lever say 4WD LOCK or 4WD AUTO? If it says lock and you are using it on pavement, then the issue when turning is that your transfer case is binding up, especially on corners. This is very bad for the chain and gears in there. The Command Trac (Lock) system is for dirt, snow, and ice where there can be some slippage of the wheels. If it says auto, then you have a different 4wd system (Selectrac) that is ok to use on pavement in all conditions.

phrogg108 · **Posted:** Mon Nov 28, 2016 12:51 pm

lfhoward wrote:

Hello,
Just checking: does your 4WD lever say 4WD LOCK or 4WD AUTO? If it says lock and you are using it on pavement, then the issue when turning is that your transfer case is binding up, especially on corners. This is very bad for the chain and gears in there. The Command Trac (Lock) system is for dirt, snow, and ice where there can be some slippage of the wheels. If it says auto, then you have a different 4wd system (Selectrac) that is ok to use on pavement in all conditions.

I typically do not use the 4WD at all on dry pavement (because there is obviously no need to normally), however, I put it into 4WD just to test the thumping noise to see if it went away and it did. But, to answer your question, yes, it was the 4WD LOCK option. There are two options, but the LOCK was the one I had it in when I heard this noise. So, good to know to NEVER use that 4WD LOCK on dry pavement. Yikes, this makes me sick to my stomach thinking about that sound. I sure hope I did not screw anything up.

lfhoward · **Posted:** Mon Nov 28, 2016 1:54 pm

Once to test it out should not cause much harm. The Jeep was just letting you know what it was thinking. :oops:

Any chance you could snap a photo of the CV joint at the back of the front drive shaft where it connects to the transfer case, and post it here? Scar0 posted a pic of what a healthy joint should look like, but it will also help you find yours underneath the driver's side. The comparison would help us diagnose the issue. If it's blown I would typically expect to see that rubber boot in the center has disintegrated and grease has been slung everywhere around where it spins.

Scar0 wrote:

A good X-fer case CV should look like this.

phrogg108 · **Posted:** Mon Nov 28, 2016 2:27 pm

lfhoward wrote:

Once to test it out should not cause much harm. The Jeep was just letting you know what it was thinking. :oops:

Any chance you could snap a photo of the CV joint at the back of the front drive shaft where it connects to the transfer case, and post it here? Scar0 posted a pic of what a healthy joint should look like, but it will also help you find yours underneath the driver's side. The comparison would help us diagnose the issue. If it's blown I would typically expect to see that rubber boot in the center has disintegrated and grease has been slung everywhere around where it spins.

Scar0 wrote:

A good X-fer case CV should look like this.

I will try and get a picture of it tonight if possible. I do know that the noise is in 2WD is getting worse. Almost sounds like something is bouncing around under the gear shift. It was a steady-ish thump before, but now it's more like rattling. Which would probably make sense if it's coming apart...

lfhoward · **Posted:** Mon Nov 28, 2016 8:53 pm

phrogg108 wrote:

I will try and get a picture of it tonight if possible. I do know that the noise is in 2WD is getting worse. Almost sounds like something is bouncing around under the gear shift. It was a steady-ish thump before, but now it's more like rattling. Which would probably make sense if it's coming apart...

I am not thinking you did any real damage beyond that one cv joint that was probably already bad. It can sound pretty gnarly when it goes. Some folks have described it as "chains dragging" or "chains jingling." When mine went out it also caused a vibration in the Jeep at 55+ mph.

New owner of a KK (2012) - thumping noise

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