Suspension-Steering Fundamentals
-
Upload
denny-dischke -
Category
Documents
-
view
243 -
download
4
description
Transcript of Suspension-Steering Fundamentals
© Goodheart-Willcox Co., Inc.
© Goodheart-Willcox Co., Inc.
Supports the weight of the vehicle Allows the wheels to move up and
down Allows rapid cornering without extreme
body roll Keeps the tires in firm contact with the
road
© Goodheart-Willcox Co., Inc.
Functions of a Suspension System
Prevents excessive body squat when accelerating or heavily loaded
Prevents excessive body dive when braking
Allows the front wheels to turn left or right for steering
Helps keep the wheels in correct alignment
© Goodheart-Willcox Co., Inc.
© Goodheart-Willcox Co., Inc.
Suspensions
Independent
Nonindependent
© Goodheart-Willcox Co., Inc.
Types of Springs
A. Coil springB. Leaf springC. Air springD. Torsion bar
© Goodheart-Willcox Co., Inc.
Coil Springs
© Goodheart-Willcox Co., Inc.
Leaf Spring Assembly
© Goodheart-Willcox Co., Inc.
Air Springs
© Goodheart-Willcox Co., Inc.
Torsion Bar
The bar resists twisting action and acts like a conventional spring
© Goodheart-Willcox Co., Inc.
Control Arm Assembly
Control arm bushings act as bearings
© Goodheart-Willcox Co., Inc.
Ball Joints
Tapered stud provides a force fit into the steering knuckle or bearing support
© Goodheart-Willcox Co., Inc.
Shock Absorber Action
© Goodheart-Willcox Co., Inc.
Gas-Charged Shock Absorbers
Use a low-pressure gas to help keep the oil in the shock from foaming
Nitrogen gas is enclosed in a chamber separate from the main oil cylinder
Gas pressure acting on the oil prevents air bubbles from forming
© Goodheart-Willcox Co., Inc.
Checking Shock Absorber Condition
Perform a visual inspection for damage, rubber bushing wear or oil leakage
Perform a shock absorber bounce test push down on one corner of the vehicle release the body count the number of times the body
rebounds maximum two or three oscillations
© Goodheart-Willcox Co., Inc.
Sway Bar (Stabilizer Bar)
Sway bar links connect the barto the control arms
© Goodheart-Willcox Co., Inc.
Front Suspension(MacPherson Strut)
© Goodheart-Willcox Co., Inc.
Strut Compressor
© Goodheart-Willcox Co., Inc.
Twin I-Beam Suspension
© Goodheart-Willcox Co., Inc.
Nonindependent Rear Suspension
Solid axle housing for rear-wheel-drive
© Goodheart-Willcox Co., Inc.
Dead Axle
Solid axle that does not drive wheels
© Goodheart-Willcox Co., Inc.
Independent Rear Suspension
This differential is mounted to the frame
© Goodheart-Willcox Co., Inc.
© Goodheart-Willcox Co., Inc.
Provide precise control of the wheel direction
Maintain correct steering effort Transmit road feel to the driver’s hands Absorb most of the road shock going to
the steering wheel Allow for suspension action
© Goodheart-Willcox Co., Inc.
Two basic kinds of steering systems are in use today: Parallelogram steering systems rack-and-pinion steering systems
Each may be operated manually or with power assist
© Goodheart-Willcox Co., Inc.
SteeringParallelogram
Steering
Basic Rack-and-Pinion Steering
© Goodheart-Willcox Co., Inc.
27
Parallelogram Steering System
Fig. 2-5Credit: ATW Assembly & Test Worldwide
© Goodheart-Willcox Co., Inc.
28
Rack-and-Pinion Steering System
Fig. 2-7Credit: ATW Assembly & Test Worldwide
© Goodheart-Willcox Co., Inc.
Steering Gears
Rack-and-Pinion Gear(rack and pinion steering)
Worm Steering Gear(parallelogram steering)
© Goodheart-Willcox Co., Inc.
Steering Rack(Rack and Pinion Steering)
© Goodheart-Willcox Co., Inc.
Steering Gear box(parallelogram steering)
© Goodheart-Willcox Co., Inc.
Power Steering Systems
Most systems use an engine-driven pump and a hydraulic system to assist steering action
An electric motor in the rack may be used to provide assist
© Goodheart-Willcox Co., Inc.
Basic Power Steering
© Goodheart-Willcox Co., Inc.
Steering Wheel Play Amount that you can turn the steering
wheel without front wheel movement Caused by worn ball sockets, a worn
idler arm, or too much clearance in the steering gearbox
Compare the play to service manual specifications e.g. 1 1/2” (33 mm)
© Goodheart-Willcox Co., Inc.
Dry Park Test
With the vehicle on the ground, rotate the steering wheel back and forth while
someone watches for part wear
© Goodheart-Willcox Co., Inc.
Steering Inspection
Raise the vehicle on a lift. Wiggle thetires back and forth while watching
for steering play
© Goodheart-Willcox Co., Inc.
Hard Steering Caused by problems with the steering
gear, power steering components, ball sockets, and the suspension system
Check the power steering pump belt for condition and tension
If the belt is slipping, hard steering could result
Check for cracks and glazing and compare tension to specs
© Goodheart-Willcox Co., Inc.
Steering System Noise Noise can be a sign of worn parts, dry
bearings or ball sockets, loose parts, slipping belts, or low power steering fluid level
Belt squeal and power steering pump noise both occur when the steering wheel is turned
Pump noise can result from low fluid level or aerated fluid
© Goodheart-Willcox Co., Inc.
Maintenance involves checking for low fluid level, incorrect belt adjustment, system leaks, and other problems
Ball socket lubrication may be necessary
© Goodheart-Willcox Co., Inc.
Checking the Fluid
Check most systems at operating temperature, with the engine off
© Goodheart-Willcox Co., Inc.
Tire Problem Under-inflated Tire
© Goodheart-Willcox Co., Inc.
Tire Problem Over-inflated Tire
© Goodheart-Willcox Co., Inc.
Tire Problem Cupping
Out of balance Lack of proper
rotation Broken belts in tire
© Goodheart-Willcox Co., Inc.
Tire Problem Alignment Problem
Worn Parts Bent Parts
© Goodheart-Willcox Co., Inc.
Alignment
Three Angles to check Camber Caster Toe
© Goodheart-Willcox Co., Inc.
Camber Positive camber
Tire leans away from vehicle
Negative camber Tire leans towards
vehicle Causes tire wear Causes vehicle
pulling
© Goodheart-Willcox Co., Inc.
47
Camber
© Goodheart-Willcox Co., Inc.
Caster Amount of upper
and lower ball joint offset
Will cause vehicle pull
Does not cause tire wear
© Goodheart-Willcox Co., Inc.
49
Caster
© Goodheart-Willcox Co., Inc.
Toe measurement
difference across front and back of tires
Will cause tire wear Will result in pulling or
wandering
© Goodheart-Willcox Co., Inc.
51
Toe Angle
© Goodheart-Willcox Co., Inc.
Tire Future Tweel
Pneumatic tire Michelin Experimented with
in Military and Off Road applications
© Goodheart-Willcox Co., Inc.
Tire Future