Front driveline grumble, worse in 4WD

So, I've seen the threads pop up about front drive-shaft issues, the CV-joint going bad in them or whatnot, and I tried searching for confirmation of what I think may be occurring, but wanted to ask to be sure.

I have a low rumble that increases with speed. It is barely noticeable when in 2WD, but in 4WD it is VERY resonating at around 40-50 MPH. It generates enough vibration to cause my dash to start rattling. It seems like it has progressively gotten worse, as I don't recall it being that loud about a year ago when I first bought it.

Anyways, how does one check the front drive-shaft to determine if it is the CV-joint? I also saw another thread that described a similar noise, but it appeared to be caused by the CV-shaft not the front drive-shaft.

So I guess I'm just checking for confirmation on what would most likely cause a speed-related grumble, that gets louder when in 4WD.

Thanks

Remove the front driveshaft and see if that helps
if not
second place I'd check is the right side CV and Intermediate shaft
both easy repairs

tommudd said:

Remove the front driveshaft and see if that helps
if not
second place I'd check is the right side CV and Intermediate shaft
both easy repairs

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Thanks!! Sounds like a plan....now...when will I have time to do it...lol

Ok so front shaft is out but here's the thing.....its only really noticeable when 4WD was engaged. With the front shaft out, its hard to tell if the vibration is still there. However, I do still notice a low rumble between 40 & 50 mph.

So now that I have the shaft out, is there anything to look for on it?

Also, how can you tell if the CV's are going bad on the axle shafts?

Thx

rear u joints.... they can be tight and still be effed... just went through that myself recently.

JLRockies said:

rear u joints.... they can be tight and still be effed... just went through that myself recently.

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Yeah, I've heard the rears are notorious for going bad, but if it was the rear u-joint why do I only get the REALLY loud rumble ONLY when in 4wd?

Front diff..

ericautopart said:

Front diff..

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Are they known for having any issues? I did a fluid change a few months ago, so it has fresh(er) fluid than it did when I bought it.

Is there anything specifically to look for? I'm pretty sure whatever it is at this point, it's not at a critical failure point or anything....I just notice things that need attention...I may even be blowing this out of proportion.

Thanks

I had a rumble and squeak only in 4WD.... then as it got worse, I got it in 2WD. The u joints are cheap and easy to replace... just sayin'

... or go replacing a bunch of hard and expensive stuff... whatever works best for you.

JLRockies said:

I had a rumble and squeak only in 4WD.... then as it got worse, I got it in 2WD. The u joints are cheap and easy to replace... just sayin'

... or go replacing a bunch of hard and expensive stuff... whatever works best for you.

Click to expand...

I may have to try that since they're not too expensive.

Thanks

OSUFANS: Always start with the simplest things first - check your tires. Don't be so quick to go to the complex solutions. Radial tires have a bad habit of slipping belts - that can cause the noise and vibration you are encountering.

A way to test the rear u joints is to run down the road a ways , then pull over and put your hand up to the rear one. If its going bad it will be HOT or pretty warm

tommudd said:

A way to test the rear u joints is to run down the road a ways , then pull over and put your hand up to the rear one. If its going bad it will be HOT or pretty warm

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Thanks Tom...however I had to laugh at this one....I believe this is about the fifth time in the last week I've seen you post this...lol

Believe me, I was planning to do this before you posted here. But thanks again! :favorites13: Cheers!

If it only happened in 4wd I doubt it's the rear u joints. Doesn't make sense. Diff problems are not common but def. possible. Plus if it only happens in 4x4 you can also rule out tires as the front tires are still spinning anyway..no? If you take off the diff cover check for metal flakes and such. I'm not sure if there is a magnet on the front diff but most of the time there it. It'll attract metal particles so you can investigate further. The intermediate shaft is also common as I've found since I sold a ton of them on the forum.

ericautopart said:

If it only happened in 4wd I doubt it's the rear u joints. Doesn't make sense. Diff problems are not common but def. possible. Plus if it only happens in 4x4 you can also rule out tires as the front tires are still spinning anyway..no? If you take off the diff cover check for metal flakes and such. I'm not sure if there is a magnet on the front diff but most of the time there it. It'll attract metal particles so you can investigate further. The intermediate shaft is also common as I've found since I sold a ton of them on the forum.

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So Eric, naturally that was what I was thinking, which is why I assumed it was front driveline related....However...I still notice the same low rumble even in 2WD, and even now with the front drive-shaft removed...it's just not as loud (not even close for that matter...but you can tell it's still there.)

So, now I'm beginning to think it's some sort of vibration coming from the rear, and is just amplified when I put the Jeep in 4x4. I still haven't checked the rear u-joint yet. I'll check that and keep y'all posted.

Thanks!