Ask Joe Mechanic: Steering and Suspensions

In the next few issues, I plan to discuss two inter-related systems, steering and suspensions. These components work hand-in-hand to control the movement of a vehicle down the road. I am going to explain the different types of steering and how they work and the same with suspensions.  I will also detail the things that need to be checked and maintained.

            The purpose of the steering system is to enable the vehicle to be pointed in the desired direction at all times. This is accomplished by using a steering box, which is connected to the wheel by a system of arms and linkages to the hub, and spindle on which the wheel and tire are mounted. A predetermined pivot point ahead of the center plane of the wheel, called the caster angle, allows the steering to be self-centering. 

            Another important control feature is the camber angle of the wheel. This is the vertical angle of the wheel and tire in relation to the road and aids in turning. A positive camber means that the top of the wheel is set outwards from the bottom wear as negative

camber means the top of the wheel is tilted inwards. The third component steering angle is toe-in. This is the horizontal angle of relationship between the two tires; with positive toe meaning the wheels are adjusted to point slightly toward each other and negative meaning the tires point slightly outward. These are the three adjustments, which aid in steering a vehicle in the correct direction and also are designed to maximize tire life. If any of these are out of specification, either by age/part fatigue, wear, or due to hitting potholes etc., this will affect your vehicle control, especially under adverse conditions and will also increase tire wear.

            The most popular type of steering in use today is the rack and pinion type. This has nearly replaced the recirculating ball type, which was in use for many years and is still used in some larger trucks and busses. The recirculating ball type used a large circular or “worm” gear, which was on the end of the steering column; this turned another gear called the sector gear. Resistance was reduced by the use of ball bearings to reduce the friction between the gears. The one weakness of this system is a “dead spot” or slight bit of play in the on center or straight-ahead position. This bit of play is required so that the steering will not bind when turned hard to either side. This play is not present with a rack and pinion system, but the recirculating ball type is adjustable to keep the play to a minimum.

            A rack and pinion steering uses a beveled pinion gear to mesh with a rack gear, which is created from a round bar of steel and has teeth machined into it. This transfers the circular motion of the steering wheel into a linear straight-line motion across the front of the car. This is thereby very precise and gives a very positive feel for the road, even when assisted by power steering. And in many newer cars, the power steering is now speed sensitive where the amount of power assist is reduced as the car moves faster.  The one drawback to rack and pinion steering is that when a steering rack begins to wear, there is no way to adjust out the play, so the rack will need to be replaced.

Next week we will cover 4-wheel and rear-wheel steering and suspensions 101.

Some of the information included in this column was sourced from Wikipedia.org articles regarding the topics of Steering, Camber Angles, etc. 

Ask Joe Mechanic: Security and Anti-Theft Tips

Most anti-theft tips are common sense, but something that we occasionally need to be reminded of. While car thefts have dropped slightly, thefts from inside vehicles have

The Club in action.

increased dramatically in the last few years. Some of this is due to the increased use of technology and part is due to the need for money to buy drugs.

            First of all, never leave your keys in the car, even if you are just running in your house to grab something or to pay for your gas or a coffee at the convenience store. This is one of the highest sources of theft of vehicles that there is.  If you leave your keys in, your insurance quite possibly will not pay off a claim. Tying into this, always lock your car, even in your own driveway during the day. An unlocked car is an open invitation for thieves to enter the vehicle. Also, do not leave cell phones, laptops, iPads or GPS units in a place where they are clearly visible.

           

A newer threat, which especially targets women, is the snatch and grab at the gas pump. What happens here is that while a lady is on one side of her car pumping gas, a thief approaches the car from the opposite side and either reaches through an open window or opens an unlocked door and grabs her purse or whatever else they can reach and jumps into a waiting car.  If you leave your purse in your car while you pump gas, either hide it or lock the doors.

            If possible, whether at home on the street, at the mall or in the airport parking lot, try to park in a well lit area. It is also safer for you if you come out to the car after dark.

Cars parked in a dark area are an open invitation for thieves and for vandalism.

            If your car is equipped with an alarm system, get small decals for the both rear side windows that state, ‘This car protected by a vehicle alarm system.’ This just may make a would-be thief think twice about targeting your vehicle. If your vehicle does not have an alarm and it sits out a lot, this may still be a wise investment.

            Another deterrent to many thieves is the “Club.” These were very popular before many vehicles were equipped with alarm systems.  However, if your car sits in a high crime area, this just might be the thing that will make a thief say this vehicle is not worth the trouble.

             And finally, when shopping for a new or used car, it is a good idea to check with your insurance agent to see if the vehicle you are considering has a high rate of theft. This could mean one of a couple things, either the parts from that vehicle are in high demand or the vehicle does not have a very good security system.