It stands to reason that if your car is equipped with rack and pinion steering, you’ve
got both a steering rack and a steering pinion, right? That’s absolutely
correct—though in reality, the steering rack and the pinion are both enclosed in
one unit commonly referred to as the steering rack. The steering rack is connected
to your steering wheel via a set of shafts and U-joints—when you turn the
steering wheel, it moves the pinion, which pushes the steering rack either to
the left or to the right. The ends of the steering rack are connected to your front
wheels so the steering rack input turns them to the left or to the right as
well. And that’s all there is to it…sort of. On lightweight sports cars, that
really is about all there is to the steering rack. The steering rack is permanently
lubricated and in many cases lasts the life of the vehicle. Most of us, however,
have a power steering rack, and that adds a whole new level of complexity
to the whole system. A power steering rack uses an engine-driven pump to supply
high-pressure hydraulic fluid to the steering rack when you turn the wheel.
While this makes it much easier to turn the steering rack, it also means that
lots of hoses, seals, and o-rings enter the picture to contain the hydraulic fluid.
On modern cars, a bad power steering rack usually translates into
a leaky power steering rack. And since a leaky steering rack can’t contain
the fluid needed for light, easy steering, the steering rack has to be replaced
with a new or remanufactured unit with all new seals and gaskets. If a shop tells
you that you need a new steering rack but you’re not experiencing any loss
of power steering fluid, get a second opinion: Most steering problems like wobbling,
play in the wheel, and wandering, aren’t caused by a bad steering rack unless
they’re accompanied by significant leakage. |
