Steering and Driving Safety
Posted on March 12, 2020
Routine Inspection is The Key to A Safe and Responsive Power Steering System
With a few exceptions, largely limited to heavy trucks and specialized vehicles, almost every car, truck, or SUV on the road uses a rack and pinion steering system to point the front tires of the vehicle in the direction you want to head.
Rather than trying to explain how the pinion turns against the rack (both are gears) to convert rotational motion into linear motion, imagine this instead. If you've ever ridden or seen video of the Pikes Peak Cog Railway or the Mount Washington Cog Railway you've seen a rack and pinion in action, as that's the system used by the rail cars to climb the steep ascent.
Original fitted only to light cars like compacts and sports car, rack and pinion steering systems required more effort to operate than the then standard recirculating ball system. But two developments changed that and a third that's coming along will alter the system even further.
First was the introduction of power steering to the rack and pinion system. In this system, the rack contains a cylinder fitted with a piston. Hydraulic hoses pass from the pinion gear to both sides of the piston. When the driver turns the wheel, fluid moves to one side of the piston or the other, turning the tires right or left.
There are two additional components to this system: the pump, which provides the hydraulic pressure, and the valve, which senses how much pressure to exert on the rack and in which direction. By the way, the first car available with power steering was the 1951 Chrysler Imperial.
The second innovation is variable ratio rack and pinion steering. In this system, the teeth at the center of the rack are spaced closer together, so the steering response is more immediate when entering a turn. As the pion gear moves closer to the edge of the rack, the teeth are spaced further apart, to slow the response rate.
The third innovation is electric power assisted steering use electric motors to provide the assistance instead of hydraulic systems. This allows engineers to better tailor the steering system to the vehicle. Electric systems also have an advantage in fuel efficiency because there is no belt-driven hydraulic pump constantly running.
The Care and Feeding Of Your Steering System
There are a number of components that require regular inspection to make certain that the rack and pinion system is operating properly and not headed toward some expensive repairs.
The first part of the inspection is the hydraulic pump. Technicians check the condition and tension of the drive belt, the condition of the pulley (to make sure the bearings are in good condition) and check all fittings for leaks. They'll also uncap the reservoir, usually on the pump, to check the fluid level.
The next steps are the hydraulic hoses that run from the pump to the rack. These should be pliable and not hard, and should show no cracking of chafing. At all points where the hoses are fitted to a component, the fitting should be dry and free of leaks. The condition of the hoses is critical as they carry power steering fluid at extremely high pressures.
The next inspection is the rack itself. The connection between the steering column and the rack is confirmed to be secure. The rack itself is checked for external seal leaks. These seals and the ball joints connected to the rack are covered by a rubber boot. The boot should be free of any tears or holes that could allow contaminants to destroy the seals. At the outer end, the ball joints live a hard life with no protection from the elements. They are one of the very few components in a modern power rack and pinion steering system that failure would have catastrophic consequences. Virtually every other component, should it fail, would allow the driver to maintain some level of control of the vehicle without the power assist.
So with a system so complicated, whose components vary from rubber hoses to hardened steel gears, that require the precise inaction of such disparate parts, it's important to have the steering system of your Chrysler, Dodge, ram, or Jeep inspected by factory-certified technicians. So visit the Caledon Chrysler website or click on the service appointment request link here to set a time to have Caledon's expert technicians inspect your steering system for both your safety and peace of mind.