Hi guys,

2001 XJ 4WD, 105,000 miles. Completely stock, no lift.

Symptoms are:
-vibration/oscillation sound, starting at about 50mph and getting worse as I go faster. Gets much louder under load. (Sound is kind of like “wubwubwubwubwubwubwub”, felt through floor/shifter/etc). Removing the front DS doesn’t change anything. Rear leafs are flat but not terrible. Can be felt through the steering wheel a bit but no major shaking like an unbalanced tire or something.

Can feel it pretty strong through my seat and the floor.

-grinding/scrape noise when I lightly feather the throttle at various speeds. Almost sounds like something is moving and settling as I touch the throttle and let off. It seems to get worse if I put it in 4HI.

So far I have replaced:
-front and rear driveshaft U Joints
-axle u joints
-all 4 wheels and tires
-front brakes
-all tie rods
-all ball joints
-track bar
-engine mounts
-trans mount
-all shocks
-all swaybar links and bushings
-both lower control arms
-steering stabilizer
-front drivers wheel hub

Any thoughts on what could be causing those symptoms?

Thanks!

 

Check the wheel bearings (most likely).

Pull the differential covers and check the bearings.

Pull the bell housing inspection panel and see if the flexplate is falling off.

 

* replace trackbar, examine all aspects, mount bolts, bush, ball joint (I presume the draglink is not the same part)..No1 likelyhood of shake imo

* upper control arm bushes become shot..its a tough job to change them

 

I replaced the trackbar (calling it a drag link here) already with a Moog one.

Do you know of any way to diagnose a bad upper control arm?

 

Check what awg said. Mine had a noise and wooble from 55 up to about 70 its a 2000 145k miles not lifted 4wd. I said hell with it as I plan on keeping it for a while and did a complete front end rebuild minus new front coil springs. Only thing really that was bad was track bar loose and bolt hole wallered out (most likely cause of the wobble) most of the rubber boots busted and lower control arms rusted out pretty bad even the metal for the bushing was pretty much gone.

 

Now my noise was like a wabwabwab though.. Bad uppper control arm look at the bushing and see if the rubber looks good and not cracked or deformed. They are pretty cheap if you want to replace anyway seeing how you have already replace a lot of stuff on it already..Does the grinding/scraping noise happen turning while moving left or right, or while hitting the breaks it changes or just straight ahead driving?

 

​​​​It is important to be able to distinguish a wabwabwab from a wubwubwub....

 

lol....I was wondering is anyone was going to notice that! Maybe it was closer to a wawawa!

 

Yeah, that's a good point. Now that I think about it, a bearing would be more like a wimwimwim.

 

Now come on wouldn't a bearing would be a wirwirwir?

 

I suppose it depends on the bearing. My front passenger hub bearing is definitely bad, and I'm getting a weemawepaweemawepaweemawepaweemawep...

 

NM, was listening to the Tokens on Classic Rock Radio...

 

I always shake at highway speeds. Try some Tylenol before hitting the road, works for me.

 

Update:

I replaced the two front axle U Joints - they were shot but no change to the noise.

Theres also a new symptom: I feel a clunk underneath my left foot when I turn the wheel to a hard right. Parked or moving, doesn’t matter. I checked all my tie rod ends and sway bar end links and they look good.

However, my track bar mount (the one that attaches it to the frame) seems to be pretty toast. I pulled the two bolts on the bottom that go into the frame and they were both destroyed towards the heads, like they had some serious vibration/shifting. One of the bolt holes was also pretty rough, like it had been deformed a bit. I bought new grade 8 bolts and washers, put them in and cranked them down quite tight. However the noise is still there, no change. The track bar itself is brand new and the axle mount looks great, no damage there.

Do you think that the track bar would still be shifting around enough to cause my heavy vibration (feels like it’s right under my seat/floor)? If so, does anyone know where I could get my hands on a stock track bar mount? I’ve looked everywhere but have only seen aftermarket models for 3”+ lifts.

Thanks!

 

Check both ends of track bar make sure all bolts tight and the holes are not enlarged now allowing it to move.