Car feels unstable at speed

[orbitron3000]

I was driving on the highway today, and I noticed that at around 55-60 mph, the car feels a little shaky -- almost like it's difficult to keep it going in a straight line. I feel a slight wobble in the steering wheel, and even with two hands on the wheel, I felt like I had a hard time keeping the car going straight.

What issues could cause something like this?

On a somewhat related question, would lowering the car (my car has stock suspension) make a stable car unstable or improve stability?

[Bitsyncmaster]

Not enough toe in can cause this. But that would not affect shaking.

[Michael]

I was driving on the highway today, and I noticed that at around 55-60 mph, the car feels a little shaky -- almost like it's difficult to keep it going in a straight line. I feel a slight wobble in the steering wheel, and even with two hands on the wheel, I felt like I had a hard time keeping the car going straight.

What issues could cause something like this?

On a somewhat related question, would lowering the car (my car has stock suspension) make a stable car unstable or improve stability?

You need to get that car on a lift ASAP and inspect every bushing, control arm, mount, TAB, tie rod, and anything else that moves....and do it soon. I don't know if I would even drive it to an inspection point, towing would not be a bad idea.

[orbitron3000]

You need to get that car on a lift ASAP and inspect every bushing, control arm, mount, TAB, tie rod, and anything else that moves....and do it soon. I don't know if I would even drive it to an inspection point, towing would not be a bad idea.

Is there anything in particular that I should be looking for? Breakages? Loose things? etc?

[Michael]

Is there anything in particular that I should be looking for? Breakages? Loose things? etc?

I would first check ball joint play, tie rod ends, control arm bushings, steering rack, and I'm sure a few other things will come to mind. The main thing is you find the problem, so look(or have a technician look) until you find it. It could very well be something about to let go and if you are at speed when a tie rod or a ball joint breaks it will not end well.

[David T]

One thing you can do immediately is to check the tires. Make sure the lug nuts are tight, you have the correct pressures, and the tires look OK. If they are over 10 years old replace them. Next would be to get on a lift and look for worn, loose, bent, broken parts while you lubricate and inspect. Also check the rear suspension, particularly the TABS. As mentioned, this is a BIG warning sign, the car should not be driven much till you can figure out how dangerous this is. Lowering a car could make it unstable.
David Teitelbaum



I would first check ball joint play, tie rod ends, control arm bushings, steering rack, and I'm sure a few other things will come to mind. The main thing is you find the problem, so look(or have a technician look) until you find it. It could very well be something about to let go and if you are at speed when a tie rod or a ball joint breaks it will not end well.

[mluder]

While caution is always a good path, I wouldn't overreact.

My car does the same thing but I have noticed it is intermittent. The steering wheel wobbles a little and the car will sway a little from time to time but it doesn't happen all the time.

I have heard the wobbling is not uncommon - could mean that the the tires need to be balance and have the toe-in checked.

As far as the hard to control... Does it happen everywhere you drive and get up to 55-60 mph? Only on certain roads? It may not be the car at all. I have found that the ruts worn into some interstates and highways from heavy traffic will cause my car to act just like you described. I attribute it to the road ruts because if I drive on a newly resurfaced highway all the shaking and swerving goes away.

Of course it all depends on what you mean by hard to control... If you really have to fight to keep in a straight line be concerned. If its just the occasional car has a mind f its own sensation search out a clean stretch of resurfaced highway and see how it feels there.

BTW - I just had my TABs replaced at DMCNW and they did an underbody inspection at the same time... They found no obvious items of concern with my suspension or steering.

That all being said, your milage may vary so take my words as a suggestion only. I don't want your wheels coming off at speed.

Cheers.
Steven

[Martyn]

Get your front wheels balanced :thumbup:

[painterdave72]

my car used to have the steering wheel vibration at speed until recently even with all new suspension stuff... i just actually replaced the front sway bar bushings with tobys kit and now the car drives perfectly stable.. no more steering vibration at all!!! Dave.

[Jimmyvonviggle]

Before doing any major surgery check that your wheels are balanced and the alignment is good.

[adam_knox]

I second the balancing. Had my alignment done thinking that was the problem, would happen at around 55-60. Everything checked out a-ok. First thing the mechanic said was get tires balanced. Sure enough, fixed the problem!

[Michael]

An out of balance tire will not cause the symptoms as you described....unless you have thrown a weight and they are REALLY out...and even then it will cause a heavy vibrating(and usually only at certain speeds). If it's JUST a vibration then I would say check for missing weights....BUT if it's as you say and it's hard to keep in a straight line and under control, then you should read my original reply and better think twice before driving it any more before diagnosing the problem.

[orbitron3000]

Now that you mention it, it really was only on one road. Driving back, I took a different route, and didn't notice really any symptoms, despite traveling roughly the same speeds. The vibrations I feel are very slight -- something similar to maybe using a power drill. I do remember it also being quite windy the day I noticed the wobbliness, so that could have caused the "car having a mind of its own" symptom. Nonetheless, I do feel that it would behoove me to get the tires balanced and check the toe and camber. I will eventually replace the suspension because the front driver side shock/spring (I'm still very new to knowing what is causing what on cars) groans when I load and unload it -- I hear a groan when I exit the car.

On a side note, does anyone know of or can recommend any reputable shops that can handle such repairs in the northern virginia area? I'm a little paranoid about taking to just any ol' service station. :umm:

[mluder]

Now that you mention it, it really was only on one road. Driving back, I took a different route, and didn't notice really any symptoms, despite traveling roughly the same speeds. The vibrations I feel are very slight -- something similar to maybe using a power drill. I do remember it also being quite windy the day I noticed the wobbliness, so that could have caused the "car having a mind of its own" symptom. Nonetheless, I do feel that it would behoove me to get the tires balanced and check the toe and camber. I will eventually replace the suspension because the front driver side shock/spring (I'm still very new to knowing what is causing what on cars) groans when I load and unload it -- I hear a groan when I exit the car.

On a side note, does anyone know of or can recommend any reputable shops that can handle such repairs in the northern virginia area? I'm a little paranoid about taking to just any ol' service station. :umm:

I recall hearing once before that Firestone shops have the data for toe and camber in their systems. I could be wrong though... The little grey cells are not what they used to... where was I?

Cheers.
Steve

[orbitron3000]

I recall hearing once before that Firestone shops have the data for toe and camber in their systems. I could be wrong though... The little grey cells are not what they used to... where was I?

Cheers.
Steve

Haha they do say the mind is the first to go :-P

Anyway, the toe and camber should be somewhere in the shop manual, shouldn't it?