Troubleshoot a Jeep problem.

[Fly320s]

My FIL's 2001 Jeep Grand Cherokee has started having an odd vibration at times.

The specs:
97,000 miles.
V8 engine. 5 liters, I think.
Auto transmission
The brake rotors are warped, which is a common issue, but the brakes work fine.

The problem:
Sporadically, the vibration starts up while at highway speeds. It feels like a wheel out of balance, but the vibration comes and goes at random times.  The vibration starts out mild, then eventually increases in frequency and intensity to the point of being nearly uncontrollable.

Slowing down to a stop by using the brakes seems to fix the issue for a time. Slowing down by coasting doesn't fix the issue.

Putting the transmission in neutral at highway speeds does not affect the vibration. Neither does revving the engine in neutral.

Any ideas?

[lupinus]

Lookup "Jeep Death Wobble"

[RoadKingLarry]

Check the U-joints.
Rotate the tires.

Adjust as needed


(eh, I had the link on the clip board)

[dm1333]

Broken ball joint?  Ask me what I-80 in Iowa will do to your lower ball joints.  Thank god I stopped and looked at my tires and saw how the tires were wearing. 

[Sergeant Bob]

Lookup "Jeep Death Wobble"

320, he's not kidding!

Death Wobble: How To Fix Your Own Case Of Dreaded Death Wobble

(If you have questions or a comment… post it below, and we’ll answer you ASAP!)

As you have already found out, ” Death Wobble ” is the horrible front end vibration that starts when one tire (usually the right tire first) hits a groove or bump in the pavement somewhere around 40~50mph.  Death Wobble is quite possibly the worst possible downside to having a coil-sprung front suspension on a vehicle with a track bar or panhard bar.  Vehicles affected by this design are the Jeep Cherokee XJ, the Jeep Grand Cherokee ZJ and WJ, TJ and JK Jeep Wrangler, and also include trucks like Toyota, Ford, and Dodge Ram (a page written specifically for the Dodge Wobble is located HERE), as well as early Ford Broncos.  Death Wobble is also extremely difficult to try to diagnose and fix, because it is actually caused by slop in the entire steering system as a whole, not by one component.  To diagnose and fix Death Wobble correctly, your mechanic needs to look for “play” everywhere in the steering and front suspension system, searching for anything that could have “play” in it.  It’s very time consuming to find a Death Wobble fix, and can be downright dangerous while you are in “testing phase”, trying to exorcise this demon from your Jeep or Truck.  This page is specific to the Jeep Death Wobble Problem and discusses Jeep Death Wobble Causes and Cures.

Death Wobble – How To Fix Your Own Case of Death Wobble

[Hawkmoon]

Lookup "Jeep Death Wobble"

^^^ This.

Basically, it's tire balance.

I have experienced true death wobble twice. The first time was in a 1999 Jeep Grand Cherokee V8, the same series as the 2001. They have a solid front axle, so what often happens is one front tire gets out of balance, and the shimmy or wobble gets transmitted to the opposite front wheel and sets that one off. If the conditions are just right (or just wrong), the two tires set up a harmonic such that each oscillation reinforces the wobble on the opposite side.

Checking the tie rod ends and track bar is recommended. Despite innumerable claims on the Internet, worn/loose tie rod ends and track bar ends cannot CAUSE death wobble, but if they are worn they are less able to dampen transmission of wobble from one side to the other side. Simply rotating the tires may help ... but it could also make things worse. The real cure is to be certain that the tires are balanced correctly. The trick is how to do that. Most shops today have equipment that's much smarter than the people who run it, so they get lazy and don't pay attention. Sometimes a Jeep with death wobble needs to be rebalanced three or four times before somebody finally gets it right. "Close" is not good enough.

At 97,000 miles, if they drive like most people and grind the steering wheel with the vehicle not moving when parking, it's probably a safe bet that the tie rod ends are in need of replacement.

[Tallpine]

Does it have a tie rod "shock absorber" ?

Old Chevy 4x4 front ends would do that when the tie rod dampener wore out.

[Fly320s]

Does it have a tie rod "shock absorber" ?

Old Chevy 4x4 front ends would do that when the tie rod dampener wore out.

Don't know. I haven't checked and I won't see it again until Monday.

Thanks for all of the replies so far.

[geronimotwo]

not being familiar with the "jeep death wobble", my bet was going to be on the cv, or u-joints.  however, i have a toyota that was expriencing similar troubles and i ended up replacing a number of worn front end parts to fix it.  are you able to check for play in the ball joints, etc?

[Fly320s]

not being familiar with the "jeep death wobble", my bet was going to be on the cv, or u-joints.  however, i have a toyota that was expriencing similar troubles and i ended up replacing a number of worn front end parts to fix it.  are you able to check for play in the ball joints, etc?

I will next week. I'll give him info and advice, but I'm not much for working on cars.

[Hawkmoon]

Does it have a tie rod "shock absorber" ?

Old Chevy 4x4 front ends would do that when the tie rod dampener wore out.

Yes, it does. But the steering damper does not "cure" death wobble, it just helps delay the onset. And a totally worn out steering damper won't result in death wobble unless the tires cause it.

At the time I experienced death wobble in the 1999 Grand Cherokee, the vehicle was about six months old, had maybe 7500 easy miles on it, and had never been off-road. The steering damper did NOT save me from the death wobble.

[Kingcreek]

I had the same problem with a 1927 model T ford.
Wear in the steering, AND/OR tire problems can cause it IMO. I'm starting to get a little of it in my F250 4x4 with 170k miles. The model T would start to shimmy so bad you almost could hold the steering wheel and the only thing to do was come to a stop and start over.

[Tallpine]

Yes, it does. But the steering damper does not "cure" death wobble, it just helps delay the onset. And a totally worn out steering damper won't result in death wobble unless the tires cause it.

At the time I experienced death wobble in the 1999 Grand Cherokee, the vehicle was about six months old, had maybe 7500 easy miles on it, and had never been off-road. The steering damper did NOT save me from the death wobble.

I'm not sure that those old split rims could ever be perfectly balanced.  And all it takes is a little mud stuck in the rims to un-balance.

As I recall, the first time I mangled the steering damper was getting stuck up to the doors in a mountain bog hole.

So do the XJ Cherokees have this same problem 

[Hawkmoon]

So do the XJ Cherokees have this same problem  

Yes.

My second episode of death wobble was in my 1988 Comanche -- which is simply the pickup variation of the Cherokee. It happened just after I had swapped on a set of used tires that were supposed to have been balanced. Took off those tires and never had another episode.

But it's only a "problem" when people try to "fix" it by replacing parts that don't need to be replaced. I've been active in multiple Jeep and 4x4 forums over the years. I have lost count of how many people have steadfastly proclaimed that a loose track bar IS THE CAUSE of death wobble. But ... the track bar on my '88 Cherokee (not the Comanche, but that one went bad, too) got very loose just about the time snow started piling up in the winter of 2000/2001. I drove it all winter, with almost a half turn of "slop" in the steering wheel due to the track bar, with no death wobble whatsoever.

The cause is tire balance. Period. Everything else is just contributory. But I don't think it's fair to characterize it as a "problem" with the XJ Cherokee as if there's a design defect with Jeep vehicles. That type of harmonic is a known problem that exists in all solid front axle vehicles. It's not peculiar to the Cherokee, or to Jeep. That '88 Cherokee is still parked outside, currently showing 287,000+ miles on the odometer. I've owned it since I bought it new in January of 1988 and it has never exhibited a hint of death wobble. All ball joints and tie rod ends are original (track bar has been replaced). But I'm fussy about tire balance. Tire shops hate me, because if I pay for it and it isn't right, I WILL make them do it over until it is right.

[Tallpine]

Ok, thanks.  I thought maybe the Jeep had a worse version of this problem, that I've had on Chevy solid axles 4x4s.

So far the 1991 Suburban has never exhibited this, even though I've gotten enough mud/rocks jammed in the disk calipers to keep the brake on one side from working temporarily.

The only way to keep tires balanced around here, is to take off the wheel/tire and pressure wash both sides about once a week 

[geronimotwo]

I have never owned a jeep, however, a vibration can be associated with anything unbalanced that is spinning at high speed.  tires, cv joints, u-joints.  in addition worn front-end parts can cause a vibration as the tire can be out of align with the track of the vehicle and the slight cross track can set off a vibration. as mentioned above, an out of balance tire may be the most likely culprit, but not the only one.

some shops will check your alignment for free and let you know if anything is loose as well.

[Gewehr98]

Reading through those threads, it appears that changing the toe-in to toe-out mitigates the problem, too.

[Sergeant Bob]

I had a 1967 Chevy pick-up which developed a severe (yet intermittent) "death wobble" at high speed. It would just about shake the steering wheel out of your hands. Turned out to be tire balance.

[Tallpine]

I had a 1967 Chevy pick-up which developed a severe (yet intermittent) "death wobble" at high speed. It would just about shake the steering wheel out of your hands. Turned out to be tire balance.

4wd ?

The one that I had the trouble with was a 1973 K-20.  It started after I got really bad stuck in the mud and had to be winched out.  Weird, it was the worst around 35-40 mph and smoothed out above that.

I finally took it to a specialized alignment shop and at first they couldn't find anything wrong with it.  Then he noticed that the tie rod damper was bent at about a 20 degree angle.  Replaced that and never had any more wobble.

[Tuco]

Sounds like a balance/suspension issue,

HOWEVER-

You say the rotors are warped.
And the vibration goes away after the vehicle comes to a stop.

Does the vibration become more pronounced with the application of the brakes?
Have the calipers ever been rebuilt or replaced?

A stuck caliper can push the pad against a warped rotor and cause a persistent, speed dependent (but not power dependent) vibration.

[Sergeant Bob]

4wd ?

The one that I had the trouble with was a 1973 K-20.  It started after I got really bad stuck in the mud and had to be winched out.  Weird, it was the worst around 35-40 mph and smoothed out above that.

I finally took it to a specialized alignment shop and at first they couldn't find anything wrong with it.  Then he noticed that the tie rod damper was bent at about a 20 degree angle.  Replaced that and never had any more wobble.

Nope. C10 2wd with a 327/325 hp. It would light up the tires with a cab-over camper on the back! Without the camper (which was as I bought it) that sucker would fly! Not real great out of the hole (easy to smoke the tires) but once it got going it would bury a 120 mph speedo and then some.

[Fly320s]

Sounds like a balance/suspension issue,

HOWEVER-

You say the rotors are warped.
And the vibration goes away after the vehicle comes to a stop.

Does the vibration become more pronounced with the application of the brakes?
Have the calipers ever been rebuilt or replaced?

A stuck caliper can push the pad against a warped rotor and cause a persistent, speed dependent (but not power dependent) vibration.

Vibration lessens when slowing, but doesn't change with brake application, other than the standard warped-rotor shimmy.

There is nothing persistent about the vibration. I didn't notice any vibrations during normal driving, except for the problem of course.

[Tallpine]

Nope. C10 2wd with a 327/325 hp. It would light up the tires with a cab-over camper on the back! Without the camper (which was as I bought it) that sucker would fly! Not real great out of the hole (easy to smoke the tires) but once it got going it would bury a 120 mph speedo and then some.

Never seen this problem on a 2wd / independent suspension. 

My mom had a 1969 C10 with a 350 and three on the tree.  It didn't really like to go under 60 mph: it would carbon up and sputter until you burned it out again.  After a couple of years, she traded it for a 1971 K10 with TH-350.  I wanted her to get a 4 speed but automatics were the big new thing in pickups about that time    It was a great truck except for the transmission.  It loved to downshift and burn gas :(