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  #37  
Old 10-05-2012, 08:19 PM
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Re: Roof rack cross bar wind noise

How do you know if the bars are on backwards? I have the shorter end in the back.
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  #38  
Old 11-07-2012, 08:06 PM
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Re: Roof rack cross bar wind noise

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Originally Posted by bahumphrey2 View Post
How do you know if the bars are on backwards? I have the shorter end in the back.
Should look like an aeroplane wing (blunt in front, tapered in back).
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  #39  
Old 11-08-2012, 08:51 AM
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Re: Roof rack cross bar wind noise

Mine also has a direction arrow sticker.
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  #40  
Old 12-23-2012, 12:56 PM
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Re: Roof rack cross bar wind noise

My father-in-law bought a 2013 Grand Cherokee Overland 3 weeks ago with a Mopar roof rack. He complained about wind noise and when I rode in the vehicle for the first time I couldn't believe how loud the noise was. Looking at this site, we determined that the noise was as much resonance as actual wind noise, and that the bars were possibly facing the wrong way despite what the factory sticker pointing "forward" indicated. We confirmed by looking at the Thule aerodynamic cross bars that, in fact, the thicker side of the bar should face forward as the leading edge with the thinner edge in the rear, exactly like an airplane wing. Ten minutes later we turned the bars around, headed out on the freeway, and noticed 100%+ improvement in the wind noise, to the point of almost being undetectable. Bottom line, the Mopar factory labeled the bars incorrectly, the Jeep dealership followed their lead, and the bars were installed incorrectly. Flip them around so the leading edge is thicker and you'll have almost no wind/resonance noise from your beloved Jeep and its roof rack.
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  #41  
Old 03-13-2013, 12:18 PM
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Re: Roof rack cross bar wind noise

Thanks to all for all the information regarding the cross bars!
I just put mine on yesterday and have a really bad wind noise. Im looking forward to getting home after reading through everyones posts and switching them. One thing, some ppl mentioned that the front vs back sticker was switched also. Do you all know if the shorter rack goes in the front or back. Right now I have the shorter one on the back......
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  #42  
Old 03-27-2013, 01:45 PM
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Re: Roof rack cross bar wind noise

Hello Jeep Garage! This is my first post. Just bought a 2014 Limited Maximum Steel. I also just put up the Mopar crossbars. I moved them 24" apart and I have them facing the right direction.

The Wind Noise is CRAZY... The rubber that fills the inner void is not sitting totally flush on top. It is seated correctly but with the pushing and prodding getting it in there its not completely flat. I read one user say that 3 days after installation the noise went away. I wonder if the rubber will heat up under the sun the next 72 hours and perhaps lay flat (If the rubber is in fact the culprit.)

I may have to ditch the racks and only use them when needed but I'd hate to do that.
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Old 03-28-2013, 12:20 AM
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Re: Roof rack cross bar wind noise

Quote:
Originally Posted by 440films View Post
Hello Jeep Garage! This is my first post. Just bought a 2014 Limited Maximum Steel. I also just put up the Mopar crossbars. I moved them 24" apart and I have them facing the right direction.

The Wind Noise is CRAZY... The rubber that fills the inner void is not sitting totally flush on top. It is seated correctly but with the pushing and prodding getting it in there its not completely flat. I read one user say that 3 days after installation the noise went away. I wonder if the rubber will heat up under the sun the next 72 hours and perhaps lay flat (If the rubber is in fact the culprit.)

I may have to ditch the racks and only use them when needed but I'd hate to do that.
I have mine moved as far apart as possible and I have no wind noise with the exception of going across one of our floating bridges when the wind is just right. Try adjusting the location of the front bar and see if that helps.
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  #44  
Old 03-28-2013, 09:16 AM
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Re: Roof rack cross bar wind noise

Thanks DirtyDuc83, I have the front bar just about as close as I can. Perhaps ill try going further.

I did try a test last evening and used paper tape across the top to ensure the rubber was completely flat. I did this only on the front cross bar and only on the front part of the crossbar (1 strip of tape). After a test drive the noise was still there. So I taped down the the front and back of both cross bars (3 more strips of tape). This resulted in a dramatic wind noise reduction. I'm almost convinced that the rubber seal is the culprit in my case.
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  #45  
Old 06-20-2013, 05:46 PM
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Re: Roof rack cross bar wind noise

ug, mine are making noise! I double checked and triple checked and I followed the stickers and the fat end is facing forward on both (the mopar sticker is toward the rear). Does the longer one go in the front or back? maybe thats the problem....
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  #46  
Old 06-20-2013, 06:11 PM
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Re: Roof rack cross bar wind noise

After my paper tape test i was convinced it was the rubber seels that were not laying flat that were the cause of the noise. I slid them out of the rack and spent a little time bending them with my hands so that I was forming a "V" or "C" shape. I then slid them back in the rack.

Result = NO WIND NOISE (Or so minimal not worth removing them)

I've had racks on the last 4 SUV's I have owned. The noise now is comparable if not better than I have had.

Hope this tip helps others.
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  #47  
Old 11-08-2014, 11:00 PM
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Re: Roof rack cross bar wind noise

Quote:
Originally Posted by krpatrick View Post
I have seen several posts on this forum concerning the OEM Mopar roof rack cross bars on the WK2, including an excellent write-up on installing them (Roof rack Cross Bar Mounting Process - Jeep Garage - Jeep Forum). But nobody seems to be complaining much about wind noise. In fact, most people praise them as aerodynamic. I had the dealer throw in the cross bars when I bought my Laredo two weeks ago and finally go around to installing them over the weekend. The wind noise is unbearable! It's the loudest whistling noise you can imagine at any speed over 35 mph. I have triple-checked that the bars in the right position (front vs. back) and that the correct edge is facing forward, according to the stickers on the bars. I have tried full-spread positioning and the owner's manual recommendation of placing them 24 in. apart. No luck. My last attempt is going to be putting the rear bar as far back as possible and then moving the front bar towards it in small increments to see if there's a position where the noise goes away or is at least tolerable. If that doesn't work, I'll just remove them and put them on only when I actually need them (i.e., ski trips). Anyone else dealing with this? I can't believe Mopar would make such an unusable item.
Agreed. That"s the only solution I have come to as well.
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  #48  
Old 11-09-2014, 12:57 AM
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Re: Roof rack cross bar wind noise

Long-time rack owner here; about 20 years and on 3 different cars. The humming is caused by a "standing wave" determined basically by two things: vehicle speed (really, air speed), and cross bar spread. The hum of the wind is like a plucked guitar string: the vibrating wind is equivalent to the plucked string, even though you don't see the wind, and the length of the guitar string is equivalent to the cross bar spread. Different lengths result in different pitch of the hum.

You'll likely notice the hum at a particular speed, and if you go significantly slower or faster than that, then the hum likely goes away. The trivial case is when vehicle speed is 0 and wind speed is 0: no noise. I'm not trying to be a smart-alec here, just trying to relate the physics of it. If, for example, you hear the hum at 35 MPH, then it's likely you will not hear the hum at 120MPH. (Likely - it all depends on the aerodynamic factors like where the rack is related to the front windshield.)

Here's the physics of it (standing wave, harmonic oscillation):
https://www.google.com/search?q=stan...&client=safari. The "nodes" are the cross bars.

You can do at least 3 things to resolve this. Test one at a time, to isolate the specific causes:

- change the bar spread; farther apart, or closer together; or
- move the front bar further forward, or further back on the roof; or
- disrupt the standing wave by adding accessories to the bar (a fairing or rack or light mounts, depends on what you want on your bar).

You may have to try all three, but I'm confident you can solve this.

One dedicated accessory for this is what Yakima calls their Yakima WindJammer. At $25 the WindJammer might be the easiest and quickest fix, but it won't fit on every type of cross bar. You might need 2 of them, one on each bar. Rotate it up/down to get the desired effect.

Picture: http://www.rei.com/zoom/618464Lrg.jpg/440

Yakima WindJammer, $25: WindJammer | Yakima

Once you have the correct setup you can leave the bars permanently mounted on your rig. That's what I've done, for some 20 years, with no humming (initially there was some, though, until I fixed it using the above). Personally, I think repeatedly mounting and removing the rack when you need it is a pain. If I had to do that, the rack would likely live on my garage floor and never be handy when I needed it.

One other related thing about this: on flatbed trucks hauling large boxes strapped down by come-along straps, the loader often puts a half twist on the strap. This helps keep the strap from vibrating like a guitar string by making it LESS aerodynamic. Similar concept.

Anyway, apologies for such a lengthy post, and good luck!
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