[Frambo]

Hi all,

One day my Jeep made a big clunk when coming to a standstill and then started making this noise at low speeds:

It's related to wheel rotation speed but is not one 'click' per wheel rotation - it is much faster than that.

Here's another vid, a bit faster

Removing the front driveshaft reduced the volume of the noise by about 95%. If I listen VERY carefully, when things are very quiet I can sometimes hear the clunk noise.

Here's what I've done (some of this stuff needed doing anyway)

Replaced CVs and shafts of front axle
Replaced CV on front DS
Replaced pinion bearing at the back of front diff
Changed Transfer case fluid

Put the front driveshaft back on and absolutely no change - noise still as present as ever so promptly removed it again.

I'm currently driving around with RWD only and pondering what to do next. The Jeep drives really nicely in rear wheel drive (where I live and drive I do a lot of full lock turning, 3 point turns, parallel parking etc) so I notice a difference - it's happier to do these turns and I don't feel like I'm fighting it.

I always that was just part of having a NV247 but my mechanic commented that when he test drove it with the front DS on, it felt like it was getting thrown around too much by undulations in the road, compared to his own WJ which has a similar set up to mine. He said he's experienced a similar sensation once before on a Range Rover with a binding centre diff.

I feel it it is something up with my transfer case - what do you guys think?

Thanks,

Fram

 

[HarryH3]

That seems to be driveshaft rotation speed related. Have you checked the u-joints on the rear driveshaft?

 

[Frambo]

That seems to be driveshaft rotation speed related. Have you checked the u-joints on the rear driveshaft?

I haven't but given that the noise is all but eliminated when I remove the front driveshaft, I figured it couldn't be related to the rear driveshaft. Or am I wrong?

 

[Frambo]

Bumping this - does anyone have any ideas?

 

[Bigrigr]

Is this Jeep AWD? Jack it up on all four corners and run it in gear while sitting still. Have a helper control the pedals and shifter while you crawl under neath to listen.....I wonder about the front pinion bearing or front output shaft bearing in the transfer case, if the rear driveline looks oK. But definatley take a listen by the rear diff while its up....

 

[Frambo]

Thanks @Bigrigr

Yes it's AWD. Front pinion bearing was replaced (there was play) but did nothing to make the sound go away. Will do as you've suggested and report back!

 

[N.B]

Hi Frambo
did you have any luck finding out what it was? Ive just searched the forum for front axle noise and I have pretty much the same sound !
Regards

 

[Double E]

In that scenario, if you are cruising along and hear that noise, drop the trans into neutral and see if the noise continues. That will tell you drive line (trans) related or something else.
When you go to put it back in D, listen for the noise again.

Also, when moving and putting the trans back in D, give the throttle a little bump to get the revs back up to where it was prior to going to neutral so there is a less abrupt change to the trans.

I've done this many times when looking for a noise myself. I've done it with my QD and QTII and my old '00 Selec-trac with no issues.

 

[Delta0]

Same size tyres all round?

With the same amount of wear?

 

[GmanWJ]

It happens that I just heard a similar noise on mine last weekend. I have the NV242HD but would hear a high frequency clicking type noise when I put it into 4H. Went away when I dropped it back into 2WD so figure it must be the TC ... front DS ujoints also possible I guess.

 

[Frambo]

Hi Frambo
did you have any luck finding out what it was? Ive just searched the forum for front axle noise and I have pretty much the same sound !
Regards

No but I suspect it is the front output bearing on the transfer case as:

1. The seal seems to be gone and it's throwing a bit of oil out

2. It decreases by about 95% with the front DS removed

In that scenario, if you are cruising along and hear that noise, drop the trans into neutral and see if the noise continues...

Yeah it continues, even in neutral with engine off

Same size tyres all round?

With the same amount of wear?

Yes indeed, I rotate them to ensure this

It happens that I just heard a similar noise on mine last weekend. I have the NV242HD but would hear a high frequency clicking type noise when I put it into 4H. Went away when I dropped it back into 2WD so figure it must be the TC ... front DS ujoints also possible I guess.

_________________________________________________

So I actually now have a bigger problem on my hands... I dropped a valve on Wednesday! It looks like I'm going to get my mechanic to swap an engine in. But here's the interesting part. While we're figuring out what's going on and what to do about it, he's lent me a WJ with the same transfer case quadradrive) and driving exactly the same routes and making the same turns it doesn't scrub at all, compared to what mine was doing with the front DS on. I had just assumed that all 247s did that but his doesn't at all. So I'm pretty sure that my transfer case was toast anyway. So I think I will replace, either with another 247 or a 242...

I'd love a 242HD but can't get one out here. Do you know if it's possible to swap in a 242 from a KJ or XJ (I have stock tyres at stock height if that helps)...