24-11-2012, 02:44 PM
Steering systems
Steering systems.ppt (Size: 1.67 MB / Downloads: 68)
Steering column
Contains and supports the steering shaft
May have a tilt mechanism
May have telescoping mechanism
Also houses ignition switch
May be designed to collapse during front impact – has plastic or soft metal rivets that are easily damaged or broken from improper use or removal
Steering column coupler
Steering column couplers allow pivot points in the column
Like a universal joint
Loose or worn couplers will result in a loose steering feel, vibration, noise, or sticky steering feel
Impact
If the vehicle is involved in a front impact, always inspect the steering column and wheel
Squeaking, chirping or rubbing sounds indicate damage
Catching, binding and play indicate damage
Especially if the airbag deploys!
Steering ratio
Steering ratio is a measurement of how many turns of the steering wheel it takes to go from a full lock to the other full lock
Basically how many turns from all the way left to all the way right
Also measured from the center (straight) to a full lock turn
Fast ratio is 3 turns lock to lock
Slow is about 4 or 5 times lock to lock
15:1 ratio – wheels move 15deg for 1 deg of steering wheel movement
Recirculating ball
Recirculating ball is used on trucks in modern vehicles
Used on most vehicles prior to 1980 and the use of front wheel drive
Uses balls on a worm gear
Has a pitman arm
Balls inside the gear ride inside guide paths
Move from one end of the ball nut through guides, back to the bottom of the housing
Uses a Parallelogram Linkage steering arm system
Pitman arm moves steering tie rods
Steering linkage
Steering linkage is anything connected to the wheels and the steering gear
Tie rods
Steering arms
Steering knuckles
Ball joints
Steering arms
Tierods attach to the front wheels at the steering arms
The steering arm is attached to the steering knuckle, which includes the spindle
Used to get proper steering angle during turns
Parallelogram
Uses tierods connected to a center link
Uses a pitman arm to move steering linkage
Also uses an idler arm to support the linkage on the passenger side