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-   -   Question about vibrations (http://www.wranglerforum.com/f274/question-about-vibrations-140551.html)

Arcticshaun 02-18-2012 03:34 PM

Question about vibrations
 
Ok I recently put a RE 4.5 short arm lift on my jk with 37's. Well now I get this very mild vibration about ever 1 second or so. Not sure if it's tires or something out of alignment. Any others have this issue ? hard to explain its not a death wobble or anything like that. It's something I can feel in my floor. And it's the same at any speed. It's consistent. Any info would be appreciated. Thanks

firehawk 02-18-2012 03:51 PM

:dance:hi, what year is your jeep, if old, jeep could be drive shaft or u joint,
also were ur new tires balanced on a hunter system. try for a rebalance.

:whistling::whistling:

Arcticshaun 02-18-2012 03:56 PM

Quote:

Originally Posted by firehawk
:dance:hi, what year is your jeep, if old, jeep could be drive shaft or u joint,
also were ur new tires balanced on a hunter system. try for a rebalance.

:whistling::whistling:

Ok 2012 jeep jk. And new drive shafts also. Tires were balanced but not sure about how.

CG3 02-18-2012 04:06 PM

Try having them (tires) road force balanced. May be what a hunter system is? I don't know that term...

Arcticshaun 02-18-2012 04:31 PM

Quote:

Originally Posted by CG3
Try having them (tires) road force balanced. May be what a hunter system is? I don't know that term...

Ok I'm running nitto trail grapplers

CG3 02-18-2012 04:35 PM

I would venture a guess that they could be difficult to balance/keep balanced due to the sheer weight of the tire? (Particularly at 37's) I really have no idea, just guessing. But road force balancing will do a better job than spin balancing. Sure worth a try.

Arcticshaun 02-18-2012 05:26 PM

Quote:

Originally Posted by CG3
I would venture a guess that they could be difficult to balance/keep balanced due to the sheer weight of the tire? (Particularly at 37's) I really have no idea, just guessing. But road force balancing will do a better job than spin balancing. Sure worth a try.

Ok thanks. Any other tips or recommendations ?

Doberguy 02-18-2012 08:29 PM

I have the same symptoms and have had many things replaced on the Jeep.
For me I think it is drive shafts or U-Joints.
As a test for yourself; when you feel the vibration take your foot offf the gas and coast at the same speed at which it happens and see if you still get the vibration.

Taking mine in soon will let you know what is found.
Good luck fixing your Jeep noise.

Arcticshaun 02-18-2012 09:59 PM

Quote:

Originally Posted by Doberguy
I have the same symptoms and have had many things replaced on the Jeep.
For me I think it is drive shafts or U-Joints.
As a test for yourself; when you feel the vibration take your foot offf the gas and coast at the same speed at which it happens and see if you still get the vibration.

Taking mine in soon will let you know what is found.
Good luck fixing your Jeep noise.

Sweet let me know what u find. Thanks

seanpholman 02-18-2012 10:21 PM

Sounds like a driveshaft.

Were your pinion angles adjusted? What style of driveshafts do you have? Also, you need to find out which d/s it is, so I recommend removing your front, then driving around and finding out if the vibration is still there.

Even if you have a balanced d/s, you can still get vibrations from the U-joints if the pinion angles are not set right, especially from the front. The problem is that if you have good caster on the front, it is hard to get a good pinion angle. There really is a fine balance on a lot of these kits, especially over 4-inches of lift.

Another thing to look at is what tires you have, some 37s are more round than the other. A road force balance should be able to fix any tire issues. I have 37-inch KM2s and have absolutely no tire vibrations, so they are not impossible to balance. Tire balance doesn't tend to manifest itself in a rhythmic harmonic the way driveshafts do, it tends to be felt through the wheel and cause the wheel to move back and forth. Tire balance also tends to vibrate stronger at certain speeds (say 55-60) and disappear at others.

As a tip to everyone, I would recommend you mark your wheel weights, because they tend to fall off on the trail and cause a vibration on the drive home. People don't often think of wheel weights and start looking for other things.

--Sean

firehawk 02-18-2012 10:28 PM

:dance:hi, hunter and force balance same, u mau have lost a small balance weight!! good to recheck, :wavey:

Arcticshaun 02-18-2012 10:31 PM

Quote:

Originally Posted by seanpholman
Sounds like a driveshaft.

Were your pinion angles adjusted? What style of driveshafts do you have? Also, you need to find out which d/s it is, so I recommend removing your front, then driving around and finding out if the vibration is still there.

Even if you have a balanced d/s, you can still get vibrations from the U-joints if the pinion angles are not set right, especially from the front. The problem is that if you have good caster on the front, it is hard to get a good pinion angle. There really is a fine balance on a lot of these kits, especially over 4-inches of lift.

Another thing to look at is what tires you have, some 37s are more round than the other. A road force balance should be able to fix any tire issues. I have 37-inch KM2s and have absolutely no tire vibrations, so they are not impossible to balance. Tire balance doesn't tend to manifest itself in a rhythmic harmonic the way driveshafts do, it tends to be felt through the wheel and cause the wheel to move back and forth. Tire balance also tends to vibrate stronger at certain speeds (say 55-60) and disappear at others.

As a tip to everyone, I would recommend you mark your wheel weights, because they tend to fall off on the trail and cause a vibration on the drive home. People don't often think of wheel weights and start looking for other things.

--Sean

Thanks for the info. I'm not sure what drive shafts I have but I think I'm going to take it in and have them check it. Like I said its not that bad it can bearly be felt thru the floor pans. It might be my OCD but I have to have everything perfect. So I feel it should not be this way. That's why I'm asking to see if it's a normal thing with tires or lift.

joe002 02-18-2012 10:35 PM

Quote:

Originally Posted by seanpholman (Post 2047522)
Sounds like a driveshaft.

... so I recommend removing your front, then driving around and finding out if the vibration is still there...

x2

There's been more than one thread on transfer cases grenading in the front after getting a lift and driving on the freeway with a vibration...

Arcticshaun 02-18-2012 10:39 PM

4 Attachment(s)
Here's some pics. I really like the way it looks and rides great with the fox resis but I don't think it should do the vibrating and just want to make sure all was adjusted to specs. So might take it to a new shop to just have a second opinion and see what they say.

Attachment 98181



Attachment 98182



Attachment 98183



Attachment 98185

joe002 02-18-2012 10:56 PM

You may want to verify the vibration yourself by at least removing the front shaft and see if the vibration goes away. Here are four examples of grenaded transfer cases while driving at freeway speeds...
http://inlinethumb52.webshots.com/43...600x600Q85.jpg

http://desmond.imageshack.us/Himg8/s...jpg&res=medium

http://i230.photobucket.com/albums/e...l/DSC04953.jpg

http://i579.photobucket.com/albums/s...g?t=1260242921

seanpholman 02-18-2012 11:01 PM

Quote:

Originally Posted by Arcticshaun (Post 2047574)
It might be my OCD but I have to have everything perfect. So I feel it should not be this way. That's why I'm asking to see if it's a normal thing with tires or lift.

Don't worry, I am totally OCD about vibrations and have 98% of them tracked down on mine. ;)

There is no reason a lifted Jeep can go down the road straight and smooth.

Checking your pinion angles is going to be key. If you have double cardan style/U-joint in the back, your driveshaft and rear pinion should be the same angle, even a couple of degrees of difference can cause a vibe. Ideally it is the same with the front, but you have to take in to account caster. It is important to remember that the '12 JK driveline is tilted at a 9 degree angle, compared with the '07-'11, which is a 6 degrees. This means that it is a straighter shot for the rear d/s, but the front has to take a steeper dive than before to reach the front axle, exacerbating the vibration issue.

--Sean

Arcticshaun 02-18-2012 11:12 PM

Quote:

Originally Posted by seanpholman

Don't worry, I am totally OCD about vibrations and have 98% of them tracked down on mine. ;)

There is no reason a lifted Jeep can go down the road straight and smooth.

Checking your pinion angles is going to be key. If you have double cardan style/U-joint in the back, your driveshaft and rear pinion should be the same angle, even a couple of degrees of difference can cause a vibe. Ideally it is the same with the front, but you have to take in to account caster. It is important to remember that the '12 JK driveline is tilted at a 9 degree angle, compared with the '07-'11, which is a 6 degrees. This means that it is a straighter shot for the rear d/s, but the front has to take a steeper dive than before to reach the front axle, exacerbating the vibration issue.

--Sean

Great. Man I appreciate all the info. This is why I live this site and I need to meet some jeep gurus so I can figure this stuff out myself in the future. Thanks again

seanpholman 02-18-2012 11:26 PM

Oops, that was supposed to read there is no reason a lifted Jeep "can't" go down the road straight and smooth.

Good luck and let us know what you find. Jeep looks good.

--Sean

Arcticshaun 02-19-2012 11:11 AM

Quote:

Originally Posted by seanpholman
Oops, that was supposed to read there is no reason a lifted Jeep "can't" go down the road straight and smooth.

Good luck and let us know what you find. Jeep looks good.

--Sean

Lol I figured that


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