Low speed rumbling noise

[dude1116]

Hi folks. Wondering if I can get some opinions or ideas thrown at me as I'm stumped.

While driving in 2WD, I get a rumbling noise and feeling all throughout the Jeep when I let off the gas, and it's mainly noticeable at lower speeds. I feel it in the seat and in the steering wheel. It seems to vibrate the whole vehicle. So I decided to do some checking:

1) Tcase CV joint was bad again. Removed driveshaft, still vibrating.

2) Checked the rear driveshaft. Doesn't seem to be much if any play there. It DOES however seem to move up a very very VERRRRRYYYY small amount if I push it that way, which seems to move the tcase up as well.

3) Found some ATF over by the tcase...haven't figured out from what yet. Trans looks good and full and tcase is also full.

4) Engine is topped off with oil.

Can someone point me to what I'm missing? I'm stumped. If it has to do with gas I figured it's driveline based but it seems I checked most things that would cause it.

 

[Cardhu]

does it change when you steer side to side. if so cv joint.

 

[Atrus]

No sound when on the gas? Is the sound speed dependent at all? If yes, then I'd suspect wheel hubs.

 

[dude1116]

No change when steering. It is speed dependent. But i cant seem to tell if its coming from a wheel or not.

 

[ChiefRudy]

Does it mostly happen when going up a low grade hill, around 35MPH and your foot is lite on gas?

Mines done a little a rumble under those conditions I described since I had my Jeep new. Had it checked several times by different garages. Nothings out of place.

 

[dude1116]

Does it mostly happen when going up a low grade hill, around 35MPH and your foot is lite on gas?

Mines done a little a rumble under those conditions I described since I had my Jeep new. Had it checked several times by different garages. Nothings out of place.

No sir. No matter the grade it happens. It's pretty loud at 25MPH and gets louder and more grumbly when speed goes down.

Anyone have any idea how to check if my wheel hub is bad?

 

[CzarKJ]

First things first... wheel off balance? Was the case for me so rotate them around to see if it is. I would also suspect rear driveshaft U-joint.

 

[dude1116]

First things first... wheel off balance? Was the case for me so rotate them around to see if it is. I would also suspect rear driveshaft U-joint.

I don't think it's a wheel-off-balance kind of rumbling. I've had my wheels heavily unbalanced before (my shops wheel balance machine was calibrated completely incorrectly) and that's more of a shaking and it's more prevalent at high speeds. If I'm getting no play in either rear driveshaft U-joint how can I really tell it's bad?

 

[dude1116]

2 questions:

1) How do I tell if a wheel hub is bad?

2) How do I tell if a U-joint is bad? (One that does not have a lot of play at the joint).

 

[02redKJ]

2 questions:

1) How do I tell if a wheel hub is bad?

2) How do I tell if a U-joint is bad? (One that does not have a lot of play at the joint).

Answer to both of your questions are the same. Open it up and inspect them. The wheel hub should have no in out movement. The U-joint may have worn needle bearings, or even be rusted inside, which will cause a vibration. May still be tight, or even too tight, because the rust fills up the area where the worn bearings used to be. You may even see some rust coming out the little boot. My guess is U-joints. Easiest to inspect too. Good place to start anyway.

 

[tjkj2002]

2 questions:

1) How do I tell if a wheel hub is bad?

2) How do I tell if a U-joint is bad? (One that does not have a lot of play at the joint).

1-jack up wheel(s) and check for any play,spin wheel and listen for noise.test drive and turn sharply left and right is noise changes you have a bad unit bearing.


2-remove driveshaft and check joints that way.

 

[dude1116]

1-jack up wheel(s) and check for any play,spin wheel and listen for noise.test drive and turn sharply left and right is noise changes you have a bad unit bearing.


2-remove driveshaft and check joints that way.

Thank you very much! Will be getting to these ASAP.

 

[dude1116]

OK did some checking. The only wheel that has even the slightest amount of play is the rear, passenger wheel (the main drive wheel). But I swear when I say slightest I mean SLIGHTEST. Like I'm pretty sure it's ALWAYS been like that. It probably doesn't even move 1/16 of a millimeter. Just enough to tell its moving, but not nearly enough to SEE that it's moving.

I think I'm going to start with the U-joints. I don't mind doing both of them if they're cheap. So I have some questions to go along with that:

1) Are the front and rear U-joints on the rear driveshaft the same part? If so, can someone give me a link to a good part? If not, can someone give me TWO links to good parts? I can't really tell much of a difference between the parts but have a basic understanding of a U-joint, how it works, and how it comes apart.

2) Can someone please tell me how to get the t-case end of the rear driveshaft off? I don't see any bolts like I do on the rear portion.

Thank you so so much everyone!

 

[Gyro]

1 They are the same
2 Front is on a splined shaft, remove rear first and front slides out.
Mark the yokes so they are put on the same way they came off.

Gyro

 

[Snail Farmer]

I just bought u-joints for mine from Napa. I got the greasable ones. Not sure if it's the part number, but it says 369 on the box. Same one for both ends. $15 a piece.

 

[CactusJacked]

Don't know which kind you got, but the u-joints with the grease fitting on the end of the bearing cap is stronger than the ones with the fitting on the trunnion. My brand preference is Spicer.

 

[dude1116]

1 They are the same
2 Front is on a splined shaft, remove rear first and front slides out.
Mark the yokes so they are put on the same way they came off.

Gyro

I just bought u-joints for mine from Napa. I got the greasable ones. Not sure if it's the part number, but it says 369 on the box. Same one for both ends. $15 a piece.

Don't know which kind you got, but the u-joints with the grease fitting on the end of the bearing cap is stronger than the ones with the fitting on the trunnion. My brand preference is Spicer.

Thank you so much guys!!! :cheers:

 

[dude1116]

So I can't manage to get the driveshaft out from either end. Any hints or tips for me???

Thank you!!

 

[02redKJ]

Did you get the U bolts off at the rear differential? Or are they the kind that are held in with a clip? If it is the U-bolt kind, then just tap on the U-joint caps and they should come loose, then the drive shaft should just pull out of the transfer case out-shaft. If it is the clip type, then you may have to use a little more force and get a socket of similar size and tap it out until the U-Joint is loose enough to come out. Then just tap the caps out.

 

[CzarKJ]

Hit it with your purse mary :rotflmao: