bobvalli

I might as well call this Project Vibration Extermination.

I picked up a 98XJ 4x4 4.0 at the beginning of the summer. One of my biggest mistakes was not driving the 30 miles to get to a highway to test it at highway speeds. Sure enough , once I get it there I find it's got a vibration. And so the quest begins....

So far I've done

shocks
leaf u-bolts (they were moving around)
u-joints (new rear [even a different rear DS] and removed front DS)
tranny mount
Hub bearings x2
tie rod
drag link
steering stabilizer (the 3 above all Crown HD)
track bar (w/ axle mod)
upper and lower control arm bushings
new tires and had them balanced x2
alignment
front and rear brakes
sway bar link ends
harmonic balancer
check inside tranny inspection cover, checked bolts, seemed OK

My mechanic and a reputable alignment shop both say the ball joints are good. The motor mounts looked good. So now I'm getting desperate because it still vibrates (even though it gets a little better with each repair).

I read a thread on DW and the guys says "even though the whole front end was tight with a fresh alignment, a Jeep mechanic told me to set the toe out a little and it cured my DW"

Has anyone heard of or done this? Did it work?

Anything other ideas (cause man!!!! I need help)

TIA

-bob-

xjinch

I had a very bad case of DW (actually knew it had it when i bought it) and ended up replacing the Trac bar with a rusty's (bushing on both ends) and the drop bracket. It did fix my death wobble but the tires I run give me slight shakes and vibrations which sometimes make me think I am getting DW back again, fortunately it is just the tires.

With that in mind, I took it to les schwab and they put it on the rack and gave me the print out, I do have a slight toe out....

I have asked many people about this (my neighbor and his family own about 19 xjs and have wheeled them for many many years) and many other "experts" seems like this. it seems this a popular fix for cherokees (toe out) and it seems to help mine...

one question for you though, have you looked at the Lower Control Arm brackets? there are a few on here who have bent and re-straightened them, so I took a look and found my passenger side looks like it has been tweaked, this affected my caster (was a little different on the Les Schwab print out) and I believe causes my front tires to scrub and fight each other a little. which may be part of my slight vibrations around 35 (very slight now that I have a heavy duty Trac Bar)

Good luck on your search for DW cure, hope this helps a little.

UserID6095

Never heard about toe out being the cure to DW.

Few questions...

Lifted or stock height?

Is this really DW or a speed specific vibration? You hit a bump and the front end starts shaking left to right and its hard to control the steering wheel? Or you hit a certain speed and then you feel vibes in the floor? Steering wheel?

goneboating06

i got the death wobble before i lifted my jeep..... the trac bar and ball joints were bad, so i replaced both and upgraded the track bar to an adjustable.... worked for a little while, then i lifted it 5 inches and got an alignment and it was fine for a while, so i took it on a 800 mile journey and on my way home as i was coming through Moab Utah, the jeeping capitol of the U.S of all places haha, and started getting the death wobble BAD! i could hardly go anywhere, and i still had a 5 hour drive home.. so i took it around to several people..... we checked and all the linkages and everything in the front end were solid tight.... still death wobble... so i took it to an alignment place, they rotated the tires... didn't work, they aligned it, didn't work, they adjusted some other crap... still didn't work.... so by now it was around 5 pm, and i had been there for over 6 hours, so i finally took it to this jeep shop right before it was about to close and told him i don't care what it costs just help me fix it because i needed to be back home... he stood back, and looked at it for all of 2 seconds and said, set your toe a little bit out, and it will fix it. Well, i figured i might as well try it and so a did it, and sure enough no more death wobble, and its been going for 4 months now with not even the slightest hint of death wobble.... The simplest and cheapest thing ended up being my cure. He said that its one of the number one causes of death wobble aside from ball joints, and a bad track bar. So setting the toe out fixed my DW....

bobvalli

Thanks

One of the things I looked at recently was whether it had shims behind the LCA clevis. I never even knew they were supposed to be there until checking out the Mopar parts catalog where they were pictured. When I checked that out the brackets didn't look like they'd be hammered or bent. I didn't see the shims though (they must be really small or just not there). I wondered about that a little.

So your TB has bushings on both ends? You have an actual bolt running up through the bushing and in to the frame mount? Is it an adjustable type? Did you have any problems with the frame end TB mount itself (was it worn or loose)?

Assuming the alignment is to "factory specs" now, you wouldn't happen to know how much to adjust it (approximately)?

Thanks

-bob-

bobvalli

TRS
It's stock. It starts at a certain speed (about 72), and gets worse the faster I go (with a few little spots of harmonic balance where it dies down a little). I know it's funny complaining about a vibration at that speed, but in CT you'll be picking 18 wheeler bumper out of your butt if you go any slower. It seems to be not as bad when I drive to work early in the morning and worse on the way home (temps?). I feel it in the floor and I kind of feel it a little through the wheel.

Thanks

-bob-

N20jeep

the frame end for the rustys trac bar that he is talking about has a new mount that bolts and place and mounts the trac bar like this


as for your toe. i normally adjust all jeeps to "toe in" about 3/16"

xjinch

1) I was actually talking about the mounts on the axle, I had to crawl under the front end and look forward to see that it was bent and re-straightened / kind of. still a little off.
2) the shims are to adjust the lenght of your LCA and set the caster (alnog with the upper control arms, my lower and uppers are actually 2" longer to push my axle forward) this is better accomplished with adjustable control arms
3) yes it has a bushing on both ends, very heavy duty. My old trac bar was an adjustable but the joint below the pin that went stright up was trashed, found this out by having my son turn the steering back and forth rapidly just until the tires tried to turn, and you could see the bushing jumping up and down. I included a pic of my new TB
4) cant remember exactly, will look tonight at the sheet and let you know. I believe it just .3+ may be way off on the number though (it may be just .03)

bobvalli

That mount looks pretty HD (man.... the old lady's gonna kill me when I tell her I need another part to replace a new part ??). I really should try to find the receipt to see if they printed the values.

If I had to say it's coming from......I'd have to say the right front wheel. I keep thinking ball joints (a novices opinion) but my mechanic keeps telling me if it was ball joints, it'd feel different (it would make a lot of noise, the steering would be loose, but probably not vibrate). Opinion on that?

Thanks

-bob-

phsycho

This is great...I just started getting the shakes in the front end and this is a good info feed. I lifted my jeep and haven't got it on the rack yet though.

bobvalli

There seems to be some pretty knowledgeable people on this thread right now (but we'll have to see how patient :-) ). Maybe we can both find the elusive answer.

-bob-

bobvalli

DUDE!!! Yours was the post I was reading and quoting. hahaha...wow. What's the odds that you'd read this post? Maybe it's an omen.

Thanks for writing back

-bob-

UserID6095

You replaced the drive shaft and removed the front one? Was the new DS balanced?

Not that it matters but this sounds more like a drive line vibe then DW. When my '96 was stock the front end would shake between 55 and 65mph. What fixed it for me was the trac-bar. It was loose on the axle end and would wobble at high way speeds.

With all the new parts you have into that thing it should ride like a dream. Tough call.

bobvalli

It was from a local Jeep JY. It didn't really make much difference to the vibe so I figured what the chances of both being unbalanced. I've done so much at this point that I started going back over some of the repairs. Maybe the trackbar should be my next re-visit. I did the axle mod, but maybe I should look at the frame end again just to make sure nothings moving. I'm going to kick myself if it turns out to be something I've already worked on.

Thanks

-bob-

UserID6095

Whats this axle mod you speak of?