Loose steering and vibration.

[captspillane]

I'm a Naval Architect by degree. When they build a ship they attach sensors to the engine, usually a direct drive slow speed diesel in most modern construction, and they record the frequencies of the engine. Every single rotating assembly, no matter how big or small, will have a frequency of vibration. Shipyards take great care in recording these and making sure they do not resonate with each other.

Every ship, every last one of them, has a zone of RPMs that you don't operate in. On one ship I was on I think it was 40 RPM on the two story tall massive slow speed direct drive diesel engine. At that speed the resonance would shake your coffee cup off the table and make your jaw chatter. You basically ran it less than that speed or more than that speed, never right at it. When you needed to speed it up you accelerated the engine through the rough spot as fast as you could. The throwback of the steam age is to call them "bells" but basically you have a set of evenly spaced common RPM values you type in for the motor or expect the engine crew to know how to maintain and the harmonic motion values are posted on a clipboard on the bridge warning you not to operate at that engine speed.

That's harmonic resonance. I firmly believe it is sound advice to replace the steering stabilizer early and often on your Eagle because the interaction of the axle being bolted directly to the engine will cause early wear to your components otherwise. I have seen Eagles with mediocre worn tires and worn parts rely on the stabilizer to stay road worthy. I could care less about Spirits or solid axles like XJ's and TJs, those don't matter much at all. It's just the Eagles that have an axle bolted directly to an Engine.

[JayRamb]

I'm a Naval Architect by degree. When they build a ship they attach sensors to the engine, usually a direct drive slow speed diesel in most modern construction, and they record the frequencies of the engine. Every single rotating assembly, no matter how big or small, will have a frequency of vibration. Shipyards take great care in recording these and making sure they do not resonate with each other.

Every ship, every last one of them, has a zone of RPMs that you don't operate in. On one ship I was on I think it was 40 RPM on the two story tall massive slow speed direct drive diesel engine. At that speed the resonance would shake your coffee cup off the table and make your jaw chatter. You basically ran it less than that speed or more than that speed, never right at it. When you needed to speed it up you accelerated the engine through the rough spot as fast as you could. The throwback of the steam age is to call them "bells" but basically you have a set of evenly spaced common RPM values you type in for the motor or expect the engine crew to know how to maintain and the harmonic motion values are posted on a clipboard on the bridge warning you not to operate at that engine speed.

That's harmonic resonance. I firmly believe it is sound advice to replace the steering stabilizer early and often on your Eagle because the interaction of the axle being bolted directly to the engine will cause early wear to your components otherwise. I have seen Eagles with mediocre worn tires and worn parts rely on the stabilizer to stay road worthy. I could care less about Spirits or solid axles like XJ's and TJs, those don't matter much at all. It's just the Eagles that have an axle bolted directly to an Engine.

EXACTLY!

[captspillane]

I've had four different Eagles develop a odd shake around 60 mph and then again around 85 mph. They would drive perfectly smooth at 50 mph or 75 mph or even 90 mph. The shake was very precise in frequency and very consistant in the speed it would start and then stop. Those shakes would be completely solved by replacing the steering stabilizer.

I remember being very scared of it when I was in high school. Then I went to college and drove ships. In that professional environment everyone expects vehicles to have resonance problems at precise engine speeds. It's normal.

I've also driven Eagles without any stabilizer installed at all with no problems. I drove my Spirit without one. I've never had a stickshift Eagle do it to me, only automatic 258s. I've seen many other people post the same symptoms but just for Eagles. I don't bother posting replies anymore because it just leads to arguments and name calling.

When a Pitman arm or balljoint goes it sucks all the time, any speed. It's not a harmonic motion, it's obvious slop and impending doom.

When a wheel balance weight falls off, it's a constant and annoying shake that gets worse as you go faster.

[Mernsy]

I've seen many other people post the same symptoms but just for Eagles.

When a Pitman arm or balljoint goes it sucks all the time, any speed.

My buddy's '05 TJ would go into the death wobble at roughly 35 mph on rough roads. He replaced the stabilizer to no effect. When the bad ball joint was replaced the death wobble went away.

You know, I'm not sure what you guys are trying to prove with all the info about ships and planes. My Eagle is a car, it doesn't fly or swim.
I'll stick with the automotive technician's take on this issue. Thanks Casper.

[captspillane]

By all means it could be an unsafe condition ready to break and kill you, so act accordingly and start replacing stuff and giving your steering very close scrutiny.

It's possible that ignoring the condition of your steering stabilizer will speed up the aging process and force you to replace parts earlier than you would have otherwise had to.

I'm just saying that you should assume the worst and give your car due attention and concern. I'm also saying that the steering stabilizer is an important component on an Eagle worth maintaining with the same diligence as front shocks, tires, and so forth.

It is bad advice to go as far as to tell people the steering stabilizer is worthless. Until then I was more than happy to avoid the typical forum disagreement where everyone pulls out their credentials and compares the size of what's in their pocket.

[1985amceagle]

By all means it could be an unsafe condition ready to break and kill you, so act accordingly and start replacing stuff and giving your steering very close scrutiny.

It's possible that ignoring the condition of your steering stabilizer will speed up the aging process and force you to replace parts earlier than you would have otherwise had to.

I'm just saying that you should assume the worst and give your car due attention and concern. I'm also saying that the steering stabilizer is an important component on an Eagle worth maintaining with the same diligence as front shocks, tires, and so forth.

It is bad advice to go as far as to tell people the steering stabilizer is worthless. Until then I was more than happy to avoid the typical forum disagreement where everyone pulls out their credentials and compares the size of what's in their pocket.

I understand that, the steering setup on the eagle was determined to need it, or the manufacturer wouldn't have put it in. As far as the steering stabilizer being the sole cause of death wobble, I find impossible. The steering stabilizer is there to take the shock out when you hit something on the road, so it isn't as likely to transfer the shock to the steering wheel. If you have death wobble, it's a sign that something is wore out. Stuff like tie rod ends, and ball joints are a service item

[carnuck]

You don't know what scary is till you experience Comanche death wobble for teh first time SUDDENLY at 75 mph on a 20% downhill grade while a semi is passing you on one side and an idiot Russian towing a overloaded boat and trailer easily doing over 100 passes you on the shoulder. In the meantime, your canopy clamps have come loose and only one is keeping it from blowing off with 2 of your children!

[SilentWolf8293]

Much as I would love to just start replacing parts willy-nilly I (unfortunately) work a minimum wage job less than 20 hours a week. I don't make enough money and I don't really have access to a reliable parts dealer.

[casper]

thats why its important to find WHATS wrong, and fix that first. the parts arent expensive, or hard to change. if its a pitman or idler arm, you can change them out and not worry about alignment. if its tie rod end, get it as close as you can, and  then you have to go have it aligned. thats another $60 or so bucks. and they will probably tell you other parts that are worn out, or getting close to needing replaced, so they cant get it perfect. (we get told that all the time when we send rigs to the alignment shop after replacing steering/suspension parts.)