[ForgotUsername]

Hi! I have a 2007 WK 3.7L 4x4 with 143k miles.

At speeds of about 60 and up, there's a loud drone or howl which I'm convinced has gotten worse over the ~1,000 miles since I've owned the car. I've noticed that:

-It only happens at 60mph+ AND when I'm pressing the gas-- it immediately goes away when i let off the throttle. I can coast at any speed and there is no noise.
-It doesnt seem to be associated with RPM. I downshift to 4th, the RPM's raise, but the noise stays the same.
-It gets very slightly quieter at higher speeds (80+) but is still very noticeable.
-There is NO shaking associated with it, not even vibration.
-Brakes make no difference
-Turning makes no difference
-I cant associate the noise with a specific area of the car (front/back/side).
-I am NOT experiencing any clunk when shifting through P-R-N-D (probably not relevant anyway)
-No engine lights or anything

What I've tried so far, none of which has affected it:
-Passenger front hub/bearing was replaced, I plan to do the driver front hub/bearing next.
-I cleaned out the throttle body. It was a long shot, but I read a TSB about a whine at highway speeds (TSB #09-001-07).
-Recent wheel balance and alignment was done after installing new front shocks/struts.

Edit:
-Tires were recently replaced, with no difference to the noise.
-The noise is a low frequency, deep sound. Nothing high or squealy about it.

 

[nvrdone1]

id be checking the u joints in both drive lines for any play & also check the bolts on the mounting flanges. the noise could also be from the tires. Id try rotating them side to side & reverse direction. that may make the noise go away.

 

[ForgotUsername]

Tires have been recently replaced, no difference in the noise.

I'm kinda expecting it's something in the driveline. If anyone has had their u-joints replaced (or entire driveshaft) could you share how much it cost you?

 

[nvrdone1]

are the tires the same size & brand as what was replaced or a different brand?

 

[ForgotUsername]

I don't think it's a tire issue. The new ones are a different make & model. New=Blizzak Old=Goodyear Fortera. Both sets were the same size I believe, on stock 17" wheels. The noise existed with both sets of tires.

 

[nvrdone1]

ok, so we've eliminated one possibility. next I'd check the drive line - ujoints and see if the slip yokes in the shafts are binding. also, can you put the car up on a rack & run it in gear? that would allow some one to get under it & listen for the noise.
also, does the noise happen on different roads or just in one area?

 

[nighowl2000]

When is the last time you had your rear diff serviced?

 

[fred99x]

I had a howling that was getting worse over time. I suspected the rear end. Took it to a driveline shop and they diagnosed the rear end. They opened it up and ended up putting in a rear end bearing kit. All good now.

 

[2007JeepNJ]

I am having the same exact issue which you’ve described and still dealing with it.
Got new muffler on (didn’t fix it). Brought to dealership today and they don’t know for sure but are saying it’s either a bearing in the front diff or the front drive shaft. They quoted me 1700 for the diff and 900 for the drive shaft (I believe that’s what they said). I really think it has something to do with the exhaust system which i guess I just need it to get worse and break so I know what to fix.

Looking for help also !!

Thanks,

Bill

2007 Jeep Grand Cher 3.7 - 95k miles

 

[ForgotUsername]

also, does the noise happen on different roads or just in one area?

Happens on all roads... It's been across several states, howling all the way!

When is the last time you had your rear diff serviced?

Never. This vehicle is new to me (~2 months) and I have yet to check the fluid levels, even.

They opened it up and ended up putting in a rear end bearing kit. All good now.

fred99x, any idea what that cost you to get a rear end bearing kit? I'm guessing either you or 2007JeepNJ is correct-- it'd likely be either a differential or a driveshaft. I have a very hard time thinking my situation has anything to do with exhaust since I've never heard the noise unless the vehicle is moving 60+mph.

I believe my troubleshooting to-do list is:
-I only installed one wheel bearing (passenger front) and I have the driver front sitting in the garage. I should try that first.
-I need to check my diff fluids. Or just skip it and go straight to a shop that could do diff/driveshaft work. It is freezing outside.

 

[fred99x]

The rear end bearing kit with labor was around $800. Taking it to a proper shop for an estimate will help determine where the problem is and save you some extra work.

 

[nighowl2000]

Happens on all roads... It's been across several states, howling all the way!

Never. This vehicle is new to me (~2 months) and I have yet to check the fluid levels, even.

fred99x, any idea what that cost you to get a rear end bearing kit? I'm guessing either you or 2007JeepNJ is correct-- it'd likely be either a differential or a driveshaft. I have a very hard time thinking my situation has anything to do with exhaust since I've never heard the noise unless the vehicle is moving 60+mph.

I believe my troubleshooting to-do list is:
-I only installed one wheel bearing (passenger front) and I have the driver front sitting in the garage. I should try that first.
-I need to check my diff fluids. Or just skip it and go straight to a shop that could do diff/driveshaft work. It is freezing outside.

Diff is easy to do if you have a garage. Lots of Youtube videos on how to do it.

easiest way to check your wheel bearings is to lift up all your wheels on jack stands and try and manually spin your tires. If you cant or feel grinding, that bearing is shot.

 

[ForgotUsername]

Update!

I took the car to a driveline shop to diagnose. The mechanic said it's a noise he couldn't recognize but he went under the car and found that the driveshaft CV joint needed replaced. So they replaced it. I've attached photos of the outgoing (stock) part.

After the replacement, it seemed to be quieter and I was happy...however it only lasted about a day and the noise is back again. The mechanic seems to be confused where it's coming from--he took it for a drive but said it doesn't sound like gear/differential noise. They're going to put it on a lift and inspect it for me at no charge in a few days.

As a side note, I still haven't checked the diff fluid levels. Also I only changed the passenger-front wheel bearing but not the driver-front. I will update as I learn more.

 

[nvrdone1]

do the simple stuff first --- check the diff fluid front & rear & check the t/case fluid.

 

[2007JeepNJ]

Update - Turns out my issue was due to bad front driveshaft. There was a serious back order for this part so they just rebuilt and all is good now.

 

[dmcglynn]

I too am having a very similar problem - just noticed it this week. Mine isn't only at 60, but anything higher than 45mph. I'm eager to find out what your driveline shop says.. I see you're in the Detroit area, where did you take it?

 

[ForgotUsername]

Update - Turns out my issue was due to bad front driveshaft. There was a serious back order for this part so they just rebuilt and all is good now.

I'll definitely tell the driveline shop about this, thank you!

I too am having a very similar problem - just noticed it this week. Mine isn't only at 60, but anything higher than 45mph. I'm eager to find out what your driveline shop says.. I see you're in the Detroit area, where did you take it?

I can hear it as low as 40mph but it's not very noticeable until about 55/60 and above. I took it to Drivetrain Specialists, 26400 Groesbeck Hwy, Warren, MI 48089 after hearing good reviews from a coworker.

 

[ForgotUsername]

Update, a few weeks later: It was the front driveshaft, and the problem is fixed now.

There's still a little bit of a noise, but it's not noticeable and definitely not a horrible howl anymore. I suspect that the remaining noise could be the rear driveshaft, although it's not an issue.

The backstory to this was a nightmare.
The factory part is on backorder and it was around $900 if I remember correctly. The driveline shop built me a custom driveshaft instead for about $475. The problem seemed fixed, until I was driving home one day and I heard a loud bang! The engine was running, but the car wasn't able to move itself regardless of gear. Thank god for AAA, they towed it back to the driveline shop for me. The issue was the new driveshaft-- the CV end broke, leaving part of the shaft spinning with the engine, but where it meets the diff nothing was moving. And of course that means the car won't drive. The shop told me that their builder put something together incorrectly... so they replaced the CV joint and it's all back together again and working fine. Needless to say, I can't recommend that shop anymore...

 

[99sajeep]

You're lucky it didn't do more damage when it broke.
Most of the time when a driveshaft comes apart, the loose end is still spinning and flinging around...

I've seen trucks before that lost the main drive shaft and it broke the tail-shaft housing off the transmission, bent the output shaft, and beat the crap out of the bottom of the floor! I guess a lot depends on where it breaks.

Good thing yours broke at the CV joint. Bad thing is, it still broke! Glad the shop owned-up and fixed right.

 

[dmcglynn]

Thanks for the follow-up. In the time since my last post, my growl noise has become a bit of a howl-noise. I was hoping it would warm up sooner so I could get under and take the drive-shaft off for inspection.. mother nature disagrees. I am expecting to find the same.