Jeep Wrangler Forum banner
  • Hey everyone! Enter your ride HERE to be a part of JUNE's Ride of the Month Challenge!

1 - 20 of 35 Posts

·
Registered
Joined
·
46 Posts
Discussion Starter · #1 ·
Happy New Year!

I'd appreciate firm opinions and solutions.

2004 Rubicon, all stock shape and lift. Let's assume that everything is new:

-Front end
-Shocks
-Front wheel Bearings
-Ball joints
-Mounts
-Control arms
-U-Joints

SOUND: Whoom...whoom...whooom...
SPEED: 50+ Miles
VIBRATION: 50+ Miles

NOTE: Sound & Vibration present in 2WD but go away in 4WD.

I have an idea but will require more input for the fix.

What is your opinion?

Best,
B
 

·
Registered
Joined
·
46 Posts
Discussion Starter · #3 ·
Thanks!

Tires are only at 3K and were balanced when new. No off roading.

Do you think balancing is needed again? Have you experienced the same issue and balancing solved it?
 

·
Registered
Joined
·
1,210 Posts
I have had vibrations like you are referring to that appear at certain speeds. I rebalanced my tires when they hit 25,000 miles just because, drove around town and all seemed fine. Got out on the interstate and up to speed and instantly realized they messed up the balance. Took it back to them and the back right was 3ozs off.
 

·
Registered
Joined
·
46 Posts
Discussion Starter · #5 ·
Vibration of the drive shaft - results of inspection

One more time, with the intentions of helping the JEEP community, here are my findings:

- It appears so that the new U-Joints on the double cardan joint of the front drive shaft have excessive "axial movement". Although all parts are new, this movement should be limited by using thicker retaining clips and be brought back to specs to eliminate vibration.

Here is a good video explaining the process:


I will report on the final outcome after I work on the driveshaft tomorrow.

B
 

·
Registered
Joined
·
46 Posts
Discussion Starter · #6 ·
Vibration of the drive shaft - results of inspection

UPDATE:

The axial movement of the U-Joints was adjusted to higher tolerances and tires were rotated and balanced.

THIS DID NOT ELIMINATE THE VIBRATION THAT STARTS AT ABOUT 50 M/H.

To make sure that the issue is not a mechanical and caused by the transmission, shifting was controlled and the vibration was still present at 50 M/H - independent of any gear change (BTW, auto).

Next, I am thinking of:

-FAILING DRIVESHAFT
-BAD REAR AXLE BEARINGS

Any other opinions?

BA
 

·
Registered
Joined
·
46 Posts
Discussion Starter · #7 ·
Not a fix for me

I have had vibrations like you are referring to that appear at certain speeds. I rebalanced my tires when they hit 25,000 miles just because, drove around town and all seemed fine. Got out on the interstate and up to speed and instantly realized they messed up the balance. Took it back to them and the back right was 3ozs off.
This did not fix the problem. See my "UPDATE"

Best,
BEN
 

·
Registered
Joined
·
397 Posts
Might have some info in it that might help you
www.jeep forum.com/forum/f9/diagnosing-death-wobble-fixing-non-dw-shimmies-wobbles-tj-version-2359089/
 

·
Registered
Joined
·
1,172 Posts
The thing of most importance (to me) is that is goes away in 4WD.
So when transfer case is engaged, all is well?
Check your transmission mount, the rubber piece that holds the tranny to the cross member. Maybe motor mounts, too.
Any pulsation in rotors (felt through brake pedal) when lightly applying brakes at highway speeds?
 

·
Registered
Joined
·
46 Posts
Discussion Starter · #10 ·
The thing of most importance (to me) is that is goes away in 4WD.
So when transfer case is engaged, all is well?
Check your transmission mount, the rubber piece that holds the tranny to the cross member. Maybe motor mounts, too.
Any pulsation in rotors (felt through brake pedal) when lightly applying brakes at highway speeds?
Thank you for the input.

I am good with "elimination process" :)

-New Transmission mount (MOPAR)
-New Motor Mounts
-No pulsation through the rotors
-To add, the front end is well put together and new - including the steering damper. Nothing is wobbling

The vibration comes from under the vehicle, accompanied by a rotating sound "whooom...whooom...whooom...whooom..."

Cheers,
BA
 

·
Registered
Joined
·
46 Posts
Discussion Starter · #11 ·
Might have some info in it that might help you
www.jeep forum.com/forum/f9/diagnosing-death-wobble-fixing-non-dw-shimmies-wobbles-tj-version-2359089/
Thanks BM3!

All parts you can imagine in the front end are new and of good quality, including the dreaded control arm bushing over the diff case.

The vehicle DOES NOT have a death wobble, never had.

This is an "under car vibration"

Cheers,
Ben
 

·
Registered
Joined
·
1,172 Posts
Thank you for the input.

I am good with "elimination process" :)

-New Transmission mount (MOPAR)
-New Motor Mounts
-No pulsation through the rotors
-To add, the front end is well put together and new - including the steering damper. Nothing is wobbling

The vibration comes from under the vehicle, accompanied by a rotating sound "whooom...whooom...whooom...whooom..."

Cheers,
BA

Any cupping on tires?
Still, that "goes away in 4WD" thing is bugging me...
 

·
Commercial Member
Joined
·
7,891 Posts
If it truly goes away in 4wd, it could be worn bushings in rear control arms, letting the axle slightly rotate under torque and start vibes? Going into 4hi might slightly reduce the pressure in the rear.


Have you tried removing the rear driveshift & driving in 4hi (essentially fwd) as a test?
 

·
Registered
Joined
·
46 Posts
Discussion Starter · #15 ·
If it truly goes away in 4wd, it could be worn bushings in rear control arms, letting the axle slightly rotate under torque and start vibes? Going into 4hi might slightly reduce the pressure in the rear.


Have you tried removing the rear driveshift & driving in 4hi (essentially fwd) as a test?
Hi Shark,

All control arms in the vehicle are new - that includes ALL bushings!

Have not tried you suggestion but I'll consider.

BA
 

·
Registered
Joined
·
1,172 Posts
Is this a test, and will you be giving us the right answer at the end??? :)
 

·
Registered
Joined
·
46 Posts
Discussion Starter · #17 ·
Is this a test, and will you be giving us the right answer at the end??? :)
:) Absolutely not a test!

I consider myself an "expert do-it-yourselfer" (I can rebuild engines & transmissions) and, considering that the vehicle has brand new parts -except for a few, like rear axle bearings - I am really trying to find out the reason for the 50 MH vibration

I will, of course, post the solution.

BA
 

·
Registered
Joined
·
612 Posts
I'd go back to the wheels and tires...

Verify the tires are balanced correctly and all wheels are true and torqued correctly. Also verify that the tires are true. New tires often aren't as round as they should be, and tire shops seem to get the balance 100% right about 50% of the time. lastly make sure you have the correct style lug nuts.

The "no issue in 4WD" is perplexing though. Double check the alignment.
 

·
Registered
Joined
·
97 Posts
Did you have the vibes before changing out all the stuff on your list? Had a similar problem with a Dodge/Cummins . . . it would vibrate on pavement, then when going into a long sweeper corner, it would vibrate then go out of phase, then back in phase . . . a rear brake drum wasn't centered with the wheel studs, and the front tire on the opposite tire was slightly out of balance. Took quite some time to find this.
Jacked up each mounted wheel and checked the run-out with a dial indicator. Found the problem. Good luck, vibes are hard to find sometimes.
 

·
Registered
Joined
·
46 Posts
Discussion Starter · #20 ·
Did you have the vibes before changing out all the stuff on your list? Had a similar problem with a Dodge/Cummins . . . it would vibrate on pavement, then when going into a long sweeper corner, it would vibrate then go out of phase, then back in phase . . . a rear brake drum wasn't centered with the wheel studs, and the front tire on the opposite tire was slightly out of balance. Took quite some time to find this.
Jacked up each mounted wheel and checked the run-out with a dial indicator. Found the problem. Good luck, vibes are hard to find sometimes.
While your approach may be right, will all things changed / new (including u-joint & centering yoke for the front driveshaft), I am leaning towards other possibilities like, bent driveshaft, rear axle bearings...

BA
 
1 - 20 of 35 Posts
Top