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-   -   Thump thump flap flap..under my feet (http://www.wranglerforum.com/f274/thump-thump-flap-flap-under-my-feet-242781.html)

carguyco 05-15-2013 10:28 AM

Thump thump flap flap..under my feet
 
Intermittent thump thump/flap flap that I can hear and feel under my feet....the passenger can also feel it. I noticed it with my doors on but am much more aware of it with doors off....smooth roads I can feel/hear it...rough roads not so much. I do NOT feel it in steering wheel at all.

I have been underneath with flashlight...nothing loose that I can tell....I did find the overflowing front diff oil on the vent tube due to this noise...probably not related.

it sounds like a mudflap flapping in the wind and hitting my floorboards....it gets louder and feels harder at higher speeds but is still intermittent and does not have any rhythm to it...it is not speed related, meaning it doesn't get faster at speed or anything...

I noticed my fender liners are very loose..could the wind be getting under them due to the lift? Why didn't I notice it before if this is the case...my front fenders rattle too....is that it?


I have latched the seatbelts in the back in the last 12 hours...have not driven it since...will be trying that today....because those suckers really get moving in the wind at 75 mph.

My concern I suppose is that it is suspension or driveline related and it is going to let loose and leave me stranded..any thoughts or experiences with this would be appreciated..

Thanks in advance!

BadOleRoss 05-15-2013 07:42 PM

Does this happen with the windows up? If not, it might be the drivers seatbelt where it comes out the the retractor mechanism at the floor and passes through the connector that is behind your left shoulder.....that portion of the seatbelt between those 2 points will flap in the wind from time to time.

carguyco 05-15-2013 07:58 PM

Already ruled out seatbelt. It is freaking me out. Had a guy at the local shop check everything all was tight. He also secured the fender liners

I'm starting to worry

ccoston 05-15-2013 08:04 PM

U joint on the driveshaft? Just wondering with 3.5" of lift.

Sinister6 05-15-2013 08:09 PM

Sounds like you have a Prius stuck in your tire... Or the wind is coming up under Jeep since the lift!

ilikeguns 05-15-2013 08:43 PM

i get a slight bump under my feet from my loose fender flares.. I trimmed mine and they are partially held in by zip ties so i can live with it.

carguyco 05-15-2013 09:34 PM

Doors back on today and the thump is still there but less noticeable. I feel and hear all kinds of crap because I'm a worrywart....but this has me baffled. Could it be the driveline already? I'm expecting to replace it someday just thought it would last longer.

As for the lift....I never drove my jeep WITHOUT a lift so I have nothing to compare it to.

I have also realized I started noticing the noise/feeling since hard top removal and soft top install and it got worse with door removal and less noticeable with doors going back on. Hmm

Today at 75 mph I hit some dips on the hwy and it felt/sounded like the undercarriage was falling off.


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Sinister6 05-15-2013 09:45 PM

Quote:

Originally Posted by carguyco (Post 3759928)
Doors back on today and the thump is still there but less noticeable. I feel and hear all kinds of crap because I'm a worrywart....but this has me baffled. Could it be the driveline already? I'm expecting to replace it someday just thought it would last longer.

As for the lift....I never drove my jeep WITHOUT a lift so I have nothing to compare it to.

I have also realized I started noticing the noise/feeling since hard top removal and soft top install and it got worse with door removal and less noticeable with doors going back on. Hmm

Today at 75 mph I hit some dips on the hwy and it felt/sounded like the undercarriage was falling off.


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Tony. I would have someone drive your Jeep...Don't tell them why, just have them drive it. See if they notice it. Right now you are so focused on it you are probably "hyper-sensitive" to everything.
Short of putting hard top back on and the doors and sorta running an experiment to see if you notice it. It may have been there the whole time but the doors and hard top muffled the natural sounds. Let me know if you need a hand...

carguyco 05-15-2013 09:51 PM

I had the shop foreman at Predator drive it....he felt it but not at hwy speeds.
I am hyper sensitive for sure. But I'm not imagining it so not sure what to do next.


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Sinister6 05-15-2013 10:01 PM

My guess is at highway speeds the air pressure is at a "constant high" pushing whatever is moving against something solid. But when you're in city driving the pressure increases and decreases with with your speed and whatever is moving...moves more and then you feel it more...

carguyco 05-15-2013 10:05 PM

I wish I could ride UNDER the jeep at hwy speeds. If it was front driveshaft I think it would be constant and vary with speed yes?


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Sinister6 05-15-2013 10:13 PM

You could always PULL the front drive shaft, see if that makes a difference. I'd start with the simple, first. Fenders, control arms are tight, Lug nuts etc...

7ekken 05-15-2013 10:43 PM

fender / wheel well liner slapping the inner metal ?

carguyco 05-15-2013 10:48 PM

Fender liners were secured today.


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bengen1 05-15-2013 10:57 PM

Sway bar end links? Did you disconnect and forgot to reconnect? or they could just be bad

carguyco 05-15-2013 11:07 PM

All bolts and nuts were checked today as well as bushings by myself and the shop foreman at a local jeep shop. It is a mystery and google is giving me a headache


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Lusus_Naturae 05-16-2013 12:46 AM

Can you borrow a GoPro from someone and video it from underneath as you drive? I know there are a few people on Youtube that have done that before.

carguyco 05-16-2013 12:59 AM

I now have a valid reason to buy a go pro. Awesome idea!


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kjeeper10 05-16-2013 05:36 AM

Quote:

Originally Posted by carguyco (Post 3760539)
I now have a valid reason to buy a go pro. Awesome idea!

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X2

I need to do this myself. I was able to tape my iphone to a CA to grab a DS view. Worked but phone kept shutting off :rofl:

Sinister6 05-16-2013 08:41 AM

Tony, I have a camera we could mount up and see if something is or where it is moving. I work just down the street from you...

carguyco 05-16-2013 09:19 AM

John I may take you up on that sometime very soon. I have your number. Thanks


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carguyco 05-17-2013 11:52 AM

After googleing and Binging my ass off the last few days I found this:

My last test run (yup, my last one because I figured out what it was) was at about 9PM last night and it was pretty windy. However, i figured if i waited until later at night I would have a better chance of listening and it not being drowned out by all the other road noise. Well, immediately when I hit about 65 it started again. But, this time it was pretty apparent where it was coming from. It turns out the latch able (header) front side portion of my Trektop NX was getting lifted and slammed down onto the roll bar/speaker bar. I heard it pretty clearly and felt the thump underneath my seat at the same time. I pulled over, latched the top and hit the road again. No thump. Unbelievable. I couldn't help but laugh as I felt like a total dipshit.

Decided to take the top off and see what happened....took the ENTIRE Trektop off the jeep and drove on the highway....sound gone. I'm 90% sure that was it....are you effing kidding me? I felt it in the roll bar last night on the way home from work and it was loud...so I tried this and I think it worked...I will keep this thread up to date...I just put the top back on to drive to work this afternoon so I should know soon enough...thanks for all the help!

Sinister6 05-17-2013 12:32 PM

LOL, Got a love it when it turns out be something simple But your brain had you convinced your JEEP was falling apart.

Sinister6 05-17-2013 08:16 PM

How'd it drive home, Tony?

carguyco 05-18-2013 12:22 AM

I had such a bad day I didn't even think about the jeep honestly. Except to savor the doors off top down feeling only a jeep can deliver.
The sound is there with top on and gone with top off. I'm gonna stop worrying!

Hope this thread helps others

Thanks John!


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