wheel shimmy

Im having a suspension problem (all stock) While driving on the highway, if I drive over some imperfections in the road, my tires start shimming. It feels like my right front tire. Ive taken it to two places, one a gas station while it was getting inspected: they said everything was tight and ok. Two: sears auto center who said the alienment was out (the toe was drastically out) but said no suspension problems. The alienment was done, and although my jeep hasnt duplicated the problem, it feels like there is still something wrong. Has anyone else had this problem? Id rather not take it to the dealer for fear ill get charged for nothing. There is definatly something wrong, the two times its happened its felt like I had a flat tire. Please Help!

After posting this I searched this problem. It sounds like I have a case of the "death wobble". What else other than what I have already done could I do?

There's tons of information on this board about this subject.

I would check the steering stabilizer, ball joints, and then make
double sure the alignment was true (stealer?) assuming you're
satisfied that the tires are OK.

Tricky prob - good luck.

Eagle has posted on this topic numerous times, and I will back him up on this from personal experience:

TIRE BALANCE IS CRITICAL to avoiding death wobble. For whatever reason, the XJ front end is VERY sensitive to unbalanced tires, even slightly unbalanced ones.

With unbalanced tires, and higher road speeds (55+mph), hitting a small bump in the road is enough to set up death wobble, even with all suspension/steeing linkage components in good shape.

Get your tires checked VERY carefully.

I'd back Jeff up there. I've had one of the more recent battles with Death Wobble (It's so fierce it should be bolded!). Anyway, it's a good idea to check your suspension for tightness, yes, and also your track bar, don't forget that boy, but I'll bet you that if you take it down to the shop and have the tires balanced and aligned well your problem will be gone.

Sequoia

Dissenting point of view

I think your Jeep may have Monkey Pox , sometimes known as MP.

Well, maybe not. In any case, I have to disagree with Jeff and Sequoia on the balance. Balance can be a significant factor in Death Wobble, but you mentioned that you only have the problem when you hit a bump. With a balance problem, you would at least notice a slight or moderate shimmy everytime you approached 50 - 55 MPH. If this is not the case, rule out balance.

The gas station guys might be inclined to check your tie rods and drag link for a steering complaint. They may not realize that the track bar has as much to do with steering as these other parts. I'd check your track bar bushings/joints as well as the controll arm bushings. Someone may have mis-adjusted your toe-in to cover up or resolve the other problem.

Not necessarly Max...

For me I can go up to 70MPH sometimes without a problem, but when I hit one of those little bumps on the freeway it'll throw the whole show on. Even a slightly out of balance wheel will cause this, so slight that it's almost not noticable, but when you hit the bump it causes the wheel to jump (normal), but because the balance isn't quite right instead of quickly settling out it just keeps going and going. Then the suspension can transfer the vibration of that wheel over to the other front wheel (that's what death wobble is) and boom, it's hit in big now and you have to change your underwear. (Granted, this all goes reallyi fast).

Sequoia
Oh, and 3312, I'm getting my tires balanced and aligned tomorrow morning (finally got a paycheck), I'll let you know how it shakes out with me..no pun inteneded!

Driving today 45mph, and hit a small bump... I got it. Thats the third time now. The jeep just feels loose, especially after hitting a bump. I get the feeling the jeep wants to shimmy/wobble after every bump, but only gets serious over large bumps. It feels like the whole jeep is falling apart.
This is not how I wanted to enter the world of jeeps.
thanks for all your help.
This is going to sound stupid, but how would I check the track bar.
Is that the equivalent of an anti-sway bar?

No, the track bar isn't the sway bar (you have both). Since you say it feels "loose" here's how I would approach it.

First of all, check everything out. To do this with the track bar adn the tie rods have somebody turning the wheel sslightly, just to take up all slack, while you feel each individual joint, if you feel any play/knocking it needs replacement.

There's a lot of straight bars underneth that, here's what they all are:
Track Bar: Goes diagonally from the left hand "Frame" (the XJ is unibody, so no true frame) to the right hand side of the axle, just under the steering stabilizer. This keeps your axle in it's true position (left to right) while the axle travels up and down.
Drag Link: This is the rod that goes from the pitman arm (the arm that comes off the steering box) to your right hand steering knuckle (the wheel).
Tie Rod: This goes from the drag link to your left hand steering knuckle.
Anti-Sway Bar: This goes from one side of the axle to the other.

You might replace your sway bar bushings to bring some tightness back, they're not terribly expensive and are available just about any 4WD place, get out and measure the diameter of the sway bar first, Jeep put out three different sizes.

All in all, after you get that, get your tires balanced, and the wheels aligned to the proper toe you should have a good firm feeling up there.

Sequoia

GSequoia said:

For me I can go up to 70MPH sometimes without a problem,

Even a slightly out of balance wheel will cause this, so slight that it's almost not noticable

because the balance isn't quite right instead of quickly settling out it just keeps going and going.

Then the suspension can transfer the vibration of that wheel over to the other front wheel (that's what death wobble is)

Click to expand...

70MPH isn't usually a problem. It's getting past 50MPH give or take 5MPH that'll get ya.

If the out-of-balance is so slight that you almost don't notice it, how does this amount to enough energy to affect suspension motion to a significant degree?

How does this slight imbalance "keep it going and going"?

How does the suspension transfer the vibration? Through the chassis from one spring to the other?

I had a similar problem with the Cheif when I first bought in a couple years ago. Turned out the steering stabilizer shock was missing a bolt and had loosened up a little hence the problem only surfaced at high speeds when I hit a big crack or bump. New shock and a bolt and the problem was fixed.

See my thread for my latest wobble question!

You're in Hagerstown 3312DC, what you should have done is taken it over to Bonebrakes alignment shop and had them fix it.... might have been more $$$ than having the monkeys at Sears fool with it but it would have been fixed right.
Mike B.

Well, the shimmy happeneing at 50 - 55 (or 60 or 65) and stopping above that is most likey balance. You can have tires that will only shake at a particular speed depending on their balance (and by the hit a bump I meant that if you have this spinning weight that's not true, but almost, and you hit a bump it upsets it's spin, so it's makes it easier to go erratically like it wants you, you know...?)

Anyway, I'm actually on my way out the door to get aligned and balanced, I'll let you know how it turns out for me.

Sequoia

finished installing a new steering stabilizer... let you all know how that goes tomarro... and 1986xj, your not the first person to tell me about bonebrakes...

Just one question; Has anyone looked at the shocks? Since this happens whan the XJ hit a bump would it not stand to reason that maybe the shocks could have something to do with it? One or both front wheels bounces repeatedly. Also do not forget the steering stabliser shock.
Patrick.

Alignment and balance cured me. I also did the tie rod, drag link, and steering stabilizer as well, but the alignment and balance were what finally put the bullet in it's head.

Techno: It's possible that shocks could be a factor, but mine feel very firm and aren't that old, so I'm thinking they were okay. Plus, I don't want to replace them 'til I go up another inch and a half!

Sequoia