bad vibration

Zack A · **Posted:** Thu Dec 31, 2009 4:10 pm

Today I noticed when I would let off the gas I'd have a semi-loud noise and a bad vibration. When I would get to lower speeds when braking it would vibrate the whole jeep. any idea what it could be. Seems to be shifting fine to me..

TIA

Dje Ryu · **Posted:** Thu Dec 31, 2009 6:24 pm

Could be a lot of things. Check your driveline, u-joints, tires. I'd start with the u-joints on the driveline. Can you tell about where the noise/vibration is coming from? Front/Rear? Through the steering wheel?

Zack A · **Posted:** Thu Dec 31, 2009 6:33 pm

Dje Ryu wrote:

Could be a lot of things. Check your driveline, u-joints, tires. I'd start with the u-joints on the driveline. Can you tell about where the noise/vibration is coming from? Front/Rear? Through the steering wheel?

I think its from the rear. but when it shakes you can feel it through the whole truck. It just started very suddenly. As stupid as it sounds could it be something simple like the rear end oils need to be changed? Im at a lost and dont have a lot of money to drop in repairs so im not driving it.

Boiler · **Posted:** Fri Jan 01, 2010 3:13 am

It can be deceiving where a vibration is coming from.

My guess it is any variety of bushings / bearings like u joints, ball joints, tie rod ends, etc. It is like under the tension of accelleration it doesn't flop around, but once it is unstressed it is free to vibrate.

tommudd · **Posted:** Fri Jan 01, 2010 8:59 am

kind of vague, but if its in the rear you should feel it somewhat more in the seat
I would start by checking all of the wheels to make sure the lugnuts were tight
next ujoints in the rear, they may feel tight if you just get under and shake them due to them having no grease and basically rusted solid almost. Take each things one step at a time and elimnate each thing

Zack A · **Posted:** Fri Jan 01, 2010 9:57 am

Could it be something simple like a loose bolt? We put a lift on prob 2 months or so ago. I'm at work 24hrs today so it will be afternoon tomorrow before I get a chance to look around. It may have been something from the front because the main vibration was felt from the steering wheel. I just figured you would feel it all the time not just when decelerating.

-Zack

InCommando · **Posted:** Fri Jan 01, 2010 2:20 pm

It could definitely be something that worked lose after the lift install. Accelerating/decelerating, power/coasting,etc.. puts different forces on things and what shows up under one condition won't under another.

Zack A · **Posted:** Fri Jan 01, 2010 3:44 pm

I did have a popping sound when I would turn left from the left front tire about a week before this started. Possibly related?

Zack A · **Posted:** Sat Jan 02, 2010 7:19 pm

Update: I took the tires off checked everything from the lift. I found what was making the pop in the front. UCA bolt was lose. Still have the growl and vibration when I left off the gas. It slows as the jeep slows so i'm not 100% sure it's not coming from the rear end. I figured tomorrow Im going to change the rear diff fluid and check the gears in there for any damage.

Ill advise

Zack A · **Posted:** Sat Jan 09, 2010 9:51 am

Update...again

I got under my jeep and messed with the drive shaft at the u-joint...vibration has gone away however a few what looked to be rubber peices fell off my u-joint. I've got a replacement and tried to replace it however it was so rusted in I couldn't knock it out. Anyone have any ideas on how to break the rust?

JeepinJarhead03 · **Posted:** Sat Jan 09, 2010 1:58 pm

as long as they aren't the permapressed ujoints of course

hose around the caps good with liquid wrench, or acetone+atf4 or some other penetration fluid

let it sit for awhile and do it again

now being that it is pretty chilly out, you may need to get some heat on the yoke but once the clips are out, a socket about the size of the cap, and a hammer and some relatively light tapping should push them on out

STINGN · **Posted:** Sat Jan 09, 2010 2:06 pm

are your wheels balanced?

Dje Ryu · **Posted:** Sat Jan 09, 2010 2:36 pm

Soak in a penetrating oil, as said. May take a day or two, and a few times. A couple sprays the first day, then once more on the second.... I like to use one socket slightly smaller than the caps, and one socket that's large enough for a cap to just slide into and a B.F.C-clamp. Put a good amount of pressure on everything, then tap on the yoke around the caps with a small ball peen hammer, tighten and tap. Keep doing this until the caps come out.

harsh20 · **Posted:** Sat Jan 09, 2010 8:49 pm

don't screw around with any other penetration liquid. use PB Blaster.

JMSMN · **Posted:** Sat Jan 09, 2010 10:13 pm

PB blaster os the fachiznit! (sp)

GYPSY400 · **Joined:** Sun Dec 28, 2008 4:02 pm **Posts:** 8

had the same vibration on mine.. Turns out it was the rear U-joint which was covered on powertrain warranty.. The u joint failed because the rear axle Ball Joint on top of the diff is loose - which is not warranty :furious:

Zack A · **Posted:** Thu Jan 14, 2010 1:15 pm

I got the PB Blaster. Ive been spraying it, How do I get the drive shaft out to replace it?

Thanks again guys

Jeepjeepster · **Posted:** Thu Jan 14, 2010 2:10 pm

A bad U joint on the rear shaft makes tons of sense if it was vibrating when you let off the gas.

To remove the drive shaft, remove the bolts at the rear of the DS where it bolts to the diff. Spray them with PB blaster and let them soak for a few. Mine had blue lock tite on them and were kinda hard to get out. It makes it easier if the rear of the jeep is on jack stands so you can turn the DS to get to the bolts. Then the DS will just slide out of the Tcase but youve got to take the clamp off the rubber dust boot at the tcase. Its not that hard. For the clamp you can use a pipe clamp to put that boot back on. Some use HD zip ties.

Diggerfreek · **Posted:** Thu Jan 14, 2010 2:27 pm

Or you can remove the clips that hold in the trunnion cap, and remove the two caps that connect to the yokes that can not be removed.......

tjkj2002 · **Posted:** Thu Jan 14, 2010 2:32 pm

Your best friend in removing and installing u-joints.

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=38335

bad vibration

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