Car feels like it steers off balance when I hit a bump

SEBASTIAN_PERSONAL

MEMBER
2006 BMW 325I
2WD
AUTOMATIC
176,000 MILES

I have a feeling that my car needs alignment but I'm stii a bit concern that there could still be a problem with other components around the wheels. I purchased the car from a private owner. He told me that the car skid sideways during winter fall few weeks ago. It has some damage at the passenger side front bumper and some a little bit of a bent around the outside rim at the driver side. Now the car still runs and no signs of clicking noise or loose joints and berrings. My only concern is that when I'm driving on the road and hit some bumps and potholes. It feels like my steering kinda throws the balanced off. It feels like the rear of the vehicle goes the other way and the front goes to the opposite way. Any idea where I can start inspecting the vehicle or what you might think problem is? Greatly appreciated!

1 Reply

CARADIODOC

MECHANIC
33,741 POSTS

If the steering wheel is off-center when driving straight ahead, the alignment has definitely been affected. Specifically, the two front wheels are steering in different directions, and the car is going to follow the tire with the most weight on it, until the other one hits a bump in the road.

The first step is to visit a tire and alignment shop to have the steering and suspension systems inspected. Every part needs to be "unloaded", meaning the car is raised up in a specific way to remove all forces acting on a part, then wear can be seen as unacceptable free play or movement. Inspecting all the parts requires the car to be supported in multiple ways, and inspecting some of them for that excessive free play requires two people.

Before the car's alignment is checked, be sure to inform the mechanic of this problem. There are three basic alignment angles we look at on all vehicles, but there is another one called "steering axis inclination", (SAI) that is routinely overlooked, because it only changes from crash damage or a previous service. Basically, SAI has to do with the angle the two front struts are tilted at, as viewed from in front of the car. All alignment computers measure SAI automatically, but as I mentioned, we don't bother to look at it except when we're looking for an elusive cause of a problem. No spec is given for SAI on most car models. All that is important is it must be exactly the same on both sides, generally within 0.2 degrees. Typical values range from about 28 to 32 degrees.