JKU Slight vibration

xflstl

xflstl

New member
My GF's JKU has developed a slight vibration, it feels as if it's coming from the front passenger area. It's not terrible, but certainly noticeable. It isn't tire balance as it does it exactly the same with two different sets of tires that are both balanced. I have checked the drive shafts (Visual inspection) as well as the front axle u-joints, and they appear to be in good order. The only other symptom it has is when in reverse it seems to surge a little if you have to give it any skinny pedal at all. (Not sure the surge and vibration are related) This all started a couple months ago after a minor wheeling trip. Idea's? I plan to get it to a dealer and have them check it out, but would love to figure it out prior to that.
 
xflstl

xflstl

New member
wayoflife said:
Does the vibration oscillate or is it constant? Is it something you can hear as well?
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Does not seem to oscillate, cannot hear it... Seems to be a near constant at all speeds, but certainly most noticeable at 25mph and up. Using the brakes has no pull, nor effect on the vib.
 
wayoflife

wayoflife

Administrator
Staff member
xflstl said:
Does not seem to oscillate, cannot hear it... Seems to be a near constant at all speeds, but certainly most noticeable at 25mph and up. Using the brakes has no pull, nor effect on the vib.
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By constant, does the vibration increase with speed or, is it the same, just at all speeds.
 
xflstl

xflstl

New member
wayoflife said:
By constant, does the vibration increase with speed or, is it the same, just at all speeds.
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I am pretty sure it increases with speed. I would say it is most noticeable from 25 to 60mph after 60 the road noise and bumps somewhat hide it, or it lessons some I cannot tell. Was more easy to tell with the stock tires on it, now with the MTR's the more aggressive tread sort of hides the vibration at least some.
 
wayoflife

wayoflife

Administrator
Staff member
xflstl said:
I am pretty sure it increases with speed. I would say it is most noticeable from 25 to 60mph after 60 the road noise and bumps somewhat hide it, or it lessons some I cannot tell. Was more easy to tell with the stock tires on it, now with the MTR's the more aggressive tread sort of hides the vibration at least some.
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What drive shafts are you running front and rear?
 
wayoflife

wayoflife

Administrator
Staff member
xflstl said:
Stock shafts front and rear.
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Really?? Your profile says you have an EVO Double throwdown front & Rear, how can you possibly have a front drive shaft that doesn't have a destroyed slip shaft boot? Also, with as much lift as you have, it wouldn't surprise me if your CV joint at the output shaft is starting to go bad. But, being that you feel it throughout the spectrum and you said this happened after a wheeling trip, I might inspect your rear shaft to see if maybe you've lost any weights. Not uncommon for that to happen and that would cause a vibration that could be felt at all speeds.
 
xflstl

xflstl

New member
wayoflife said:
Really?? Your profile says you have an EVO Double throwdown front & Rear, how can you possibly have a front drive shaft that doesn't have a destroyed slip shaft boot? Also, with as much lift as you have, it wouldn't surprise me if your CV joint at the output shaft is starting to go bad. But, being that you feel it throughout the spectrum and you said this happened after a wheeling trip, I might inspect your rear shaft to see if maybe you've lost any weights. Not uncommon for that to happen and that would cause a vibration that could be felt at all speeds.
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Heh, this is my Girlfriends near stock JKU that has the Vibration :) It has a 2" spring lift, matching shocks had been running this setup for near a year before the vibration started.


Here is the exact setup when vib started

2" Skyjacker spring lift/ with shocks
JKS front quik disco's / moved old fronts to rear
Brakeline relocation tabs
Stock everything else.....................

Was thinking it was a tire issue so I didn't look into it until I just recently added
Front lunchbox locker
1" body lift
35" Mtr/k Goodyears.

The tires balanced just fine but didn't stop or change at all the vibration, so now I am trying to figure it out.
 
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wayoflife

wayoflife

Administrator
Staff member
xflstl said:
Heh, this is my Girlfriends near stock JKU that has the Vibration :) It has a 2" spring lift, matching shocks had been running this setup for near a year before the vibration started.
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:cheesy: Well that would make a difference now, wouldn't it :crazyeyes:

Having said that, I would still check your rear shaft to see if any weights might have gotten knocked off.
 
xflstl

xflstl

New member
wayoflife said:
:cheesy: Well that would make a difference now, wouldn't it :crazyeyes:

Having said that, I would still check your rear shaft to see if any weights might have gotten knocked off.
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I checked that a couple days ago and noticed no spots on either the front or rear shafts that looked as if they were missing a weight, I will check again.
 
wayoflife

wayoflife

Administrator
Staff member
An alignment that's off will give you handling issues, not vibrations. Unfortunately, everyone has their own idea of what a vibration is vs. a shimmy or wobble or shake or what have you and that makes it hard to figure out what's really the cause when all you've got is what you can read on a forum like this.
 
jeeeep

jeeeep

Hooked
just looking for things to rule out and yes, vibration, shimmy, etc all are different but the same when reading about them lol
I did miss the OP entry where a lunchbox locker was added - I looked into these a sometime ago and if I recall they keep the passenger side shaft spinning even when in 2wd which might cause a DS vibration, I don't know if this is correct but one of those things in my brain that just jumped out...damn old age nothing's filed properly anymore :thinking:
 
xflstl

xflstl

New member
jeeeep said:
just looking for things to rule out and yes, vibration, shimmy, etc all are different but the same when reading about them lol
I did miss the OP entry where a lunchbox locker was added - I looked into these a sometime ago and if I recall they keep the passenger side shaft spinning even when in 2wd which might cause a DS vibration, I don't know if this is correct but one of those things in my brain that just jumped out...damn old age nothing's filed properly anymore :thinking:
Click to expand...
Well the locker is one thing I can rule out, the vibration was there prior to the locker install.
 
biggy

biggy

Member
I had a slight vibration from the front end. I ruled out driveshafts, tires etc. After driving me nuts for a month it turned out to be the driver side unit bearing. Just jack the tire just off the ground and grasp it at the top and bottom. Try to wiggle the tire in and out. There should be virtually no movement. If there is movement replace the unit bearing.

Sent from my SAMSUNG-SGH-I896 using WAYALIFE mobile app
 
wayoflife

wayoflife

Administrator
Staff member
biggy said:
I had a slight vibration from the front end. I ruled out driveshafts, tires etc. After driving me nuts for a month it turned out to be the driver side unit bearing. Just jack the tire just off the ground and grasp it at the top and bottom. Try to wiggle the tire in and out. There should be virtually no movement. If there is movement replace the unit bearing.

Sent from my SAMSUNG-SGH-I896 using WAYALIFE mobile app
Click to expand...

I agree, could very well be a unit bearing going bad. A lot of times you can hear it too but, I have seen where they just cause a vibration.
 
xflstl

xflstl

New member
biggy said:
I had a slight vibration from the front end. I ruled out driveshafts, tires etc. After driving me nuts for a month it turned out to be the driver side unit bearing. Just jack the tire just off the ground and grasp it at the top and bottom. Try to wiggle the tire in and out. There should be virtually no movement. If there is movement replace the unit bearing.

Sent from my SAMSUNG-SGH-I896 using WAYALIFE mobile app
Click to expand...

KK good advise that's one I had not checked yet.
 
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