[Mark]

I just got a 10k miles service for my car, and this also included the steering inspection. After a week of driving, I felt like my steering wheel is becoming too sensitive, it even turns itself on uneven pavement. The steering also shakes on rough road, which did not happen before the check-up. I went to my local tire shop for balancing, but still did not solve this problem. What's wrong with it?

 

[webguyIS]

Did they do a tire rotation?

Your rear tires (provided that you don't do donuts like mr Lexus_IS300) probably have more tread on them and if they rotated them to the front, there is more play with the tread since it's "taller" and more flexible. Give it a little time and I bet it goes away.

 

[ISLover]

Hey webguyIS, wouldn't the front ones have more tread on them since it's a rear wheel drive? Don't know, just wondering.

 

[webguyIS]

Well honestly if you don't drive your car like a nut, the rear tires should outlast the fronts since they're not undergoing the stress of turning all the time. Angling the wheel when going in a straight line takes miles off that tread, while the rears just follow the motion of the car.

If, however, he likes to lay rubber coming out of corners and such, then my explanation is completely shot down. =)

 

[Mark]

Thanks for the reply, but I think that my rear tires have less tread than the front (before rotation) because I drive pretty aggressive. I also checked the tire pressure and the front have like 35psi, while the rear have 32psi, so might this caused the problem?

 

[mr_is300]

I have experienced this problem as well. I'm sure when this started happening or if it is normal on this car... but when driving on uneven roads or on roads with ruts in them, the car almost seems to steer itself. I have to keep my hands on the wheel otherwise I'll get into an accident.

 

[webguyIS]

Mark, then I would have to agree that it's normal. It ain't a town car ya know! =)

 

[vlad_a]

It must be normal.
I have the same thing. Happened after I switched from winter tires to stock 17s, which I rotated. It doesn't feel as bad now as it used to. Just give it a few miles.

 

[STKSKI]

Yup, i hear that man, i grounded out my car (ahh so painful) the other day and when i was coming home my steering wheel jolted to the left. I thought it was because i messed something up when grounding it but i went back the same way that night and in the exact same spot it did it again. I saw that the pavement wasnt even.
Sam

 

[Young]

Same thing happens in my BMW. But the tire pressures you cite are probably contributing to your problems. With 35 psi in front and 32 in rear you're getting more grip in the front, so the turning tires are getting more grip and causing the veering thing to be more pronounced. If you REALLY want to experience this problem to the nth degree, try it with sticky R compound ("racing") tires. You'll really get a lot of grip with the turning tires and feel like the car is going to veer abruptly off the road every time you go over a bump or contour in the road surface. I drove with my Kumho tires for an hour and a half on LA freeways once and I was hanging onto that steering wheel for dear life.

Suggested fix: Make it 32 in FRONT and 35 in REAR.

[ May 04, 2001: Message edited by: Young ]

 

[rubley]

What everyone is experiencing is called bump steer. It is a consequence of a stiff suspension, particularly the anti-roll bar.

Originally posted by mr_is300:
I have experienced this problem as well. I'm sure when this started happening or if it is normal on this car... but when driving on uneven roads or on roads with ruts in them, the car almost seems to steer itself. I have to keep my hands on the wheel otherwise I'll get into an accident.

 

[HIBBoyScott]

Originally posted by mr_is300:
I have to keep my hands on the wheel otherwise I'll get into an accident.

considering you are driving, shouldn't your hands be on the wheel anyway?

 

[Mark]

Thanks for all the replies, but I'm still curious why the steering become much lighter (unstable) on freeway cruising, and it also shakes on rough road which didn't happen before tires rotation. I might switch the tires back to see what will happen.

 

[Young]

Mark, it really sounds as if your tire pressures are causing the difference. Normally, they should be lower in front than in back for that "stock" feel you're used to. So make it 32 psi in front and 35 in back and I think you'll experience less "bump" steer. Remember, your tires are also a part of the suspension! The stiffer they are (i.e., the more air in them) the more you'll experience this phenomenon. Also, the added grip that the higher pressure up front contributes to it as well.

At any rate, try reversing the pressures and let us know how that feels.

 

[Young]

P.S. The lighter and shakier steering can also be attributed to the tire pressures (or a bad alignment or tire balancing). I'd try reversing the pressures first. It's the simplest and cheapest thing to do.

 

[Young]

Mark, it really sounds as if your tire pressures are causing the difference. Normally, they should be lower in front than in back for that "stock" feel you're used to. So make it 32 psi in front and 35 in back and I think you'll experience less "bump" steer. Remember, your tires are also a part of the suspension! The stiffer they are (i.e., the more air in them) the more you'll experience this phenomenon. Also, the added grip that the higher pressure up front contributes to it as well.

At any rate, try reversing the pressures and let us know how that feels.

 

[Daniel]

Mark, I had a problem very similar to what you describe a month or so ago. It turns out to be an alignment problem.
I agree that this may simply be a problem with the air pressure, as I have experience this when I get lazy to check my tires every other week. But if by adjusting the tire pressure doesn't fix the problem, you should go do a 4 wheel alignment. It turns out that my front was just a bit mis-align, by 0.5 degree or so (I don't have the printout with me, so I am writing with by memory).

 

[is300soon]

u all are talking about a car with lopros, when the thread life goes away u will feel it, this stems from a tire with little groove as is. When i had my old car with 17's the first umm 12k was great, after that it was focked.