1. Steering Systems Topics covered in this presentation:
Basic Steering Systems
Linkage Steering
Rack-and-Pinion Steering
Power Steering

2. Basic Steering Systems
Two main types of steering:
Drop arm
Idler arm
Track rods
Centre link
Steering knuckles
Steering gear/box
Linkage or Conventional type (also known as Parallelogram).
Rack-and-pinion type.
Linkage type uses a worm gear inside the steering gear/box, this operates the drop arm, then couples to a centre link, idler arm, track rods and the steering knuckles.
Track rods
Rack-and-pinion
Rack-and-pinion type uses track rods to couple the rack to the steering knuckles.
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3. Question 1 What is the linkage type of steering system also known as?
A) Complicated type
B) Rack-and-pinion type
C) Parallelogram type
Correct Answer = C
D) Idler type

4. Question 2
Which type of steering system uses a worm gear inside the steering gear/box?
A) Linkage type
B) Rack-and-pinion type
Correct Answer = A

5. Steering Shafts and Columns
Nearly all steering systems use a steering column or shaft to link the driver (steering wheel) to the steering rack or gear/box.
Flexible coupling isolates steering wheel from road shocks.
Steering wheel
Steering rack or gear/box
Universal joints allow steering shaft angles to change.
Collapsible section
Flexible coupling
Most steering columns are designed with a collapsible section that helps prevent forces generated in a collision being transferred to the driver.
Universal joints
Master spline location
Bottom of steering column normally has a master spline where it mounts onto the steering rack-and-pinion or steering gear/box.
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6. Question 3
What is the name of the joint that allows the steering shaft angle to change?
A) Hinged joint
B) Universal joint
C) Hanging joint
Correct Answer = B
D) Flexible joint

7. Ball Joints
Ball joints are common on most steering systems and provide a controllable link to the other steering components.
Ball socket
Track rod end
Adjusting thread
Adjusting lock nut
Inner track rod
Ball joints allow linkage components to swivel freely.
Suspension (vertical) and steering (horizontal) movements.
Ball joint
Inner track rod
Boot
Shock damper assembly
Nearly all ball joints have some form of adjustment.
Most steering rack ends have adjustable ball joints and some incorporate shock dampers.
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8. Drop arm (connected to steering gear/box)
Linkage Type Steering System
Idler arm
Drop arm (connected to steering gear/box)
Idler arm bracket
Steering damper
Track rod assembly
Track rod assembly
Centre link
Linkage type steering has many component parts and is normally found on older vehicles.
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9. Question 4
What does the Drop arm of a linkage steering system connect to?
A) Idler arm
B) Track rod
C) Steering column
Correct Answer = D
D) Steering gear/box

10. Re-circulating ball type
Steering Gear/box Principles
Most linkage type steering systems require some form of mechanical advantage, this is provided mainly by the gear ratio in the steering gear/box.
Three main types of steering gear/box:
Worm Gear
Re-circulating Ball
Worm and roller (older Vehicles)
Worm gear type
Re-circulating ball type
Most common are “Worm Gear” and “Re-circulating Ball”.
Drop arm couples to links.
Worm drive on steering shaft.
Re-circulating ball mechanism.
Small number of teeth needed.
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11. Rack-and-Pinion Type Steering System
Rack-and-pinion steering is more precise and compact.
Uses less component parts.
Steering knuckle
Steering column
Ball joint
Steering rack
Track rod
Boot
More common on modern vehicles.
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14. Question 5
Which of the following is an advantage of a rack-and-pinion steering system over a linkage steering system?
A) It can be made larger
B) It contains fewer parts
C) It is more common
Correct Answer = B
D) It can be used on cars

15. Rack-and-Pinion Steering Principle
Pinion gear is turned by steering shaft.
Pinion meshes with rack to move it sideways.
Thrust spring holds rack against pinion to prevent backlash.
Pinion shaft is normally shimmed to minimize end float (up or down movement) also reducing backlash.
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16. Question 6
A rack-and-pinion gear, as used in a steering system, converts rotary motion to linear motion. Is this true or false?
Answer True
False
Correct Answer = T

17. Basic Power Steering Systems
Power steering uses hydraulic fluid pressure to assist steering movement.
Three main types:
Rack-and-pinion
Integral piston
External cylinder
All systems require a reservoir, pump, hoses, control valve, pressure relief valve and a hydraulic cylinder.
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18. Question 7
What substance is used to assist steering in a power steering system?
A) Compressed air
B) A vacuum
C) Hydraulic fluid
Correct Answer = C
D) Distilled water

19. Power Rack-and-Pinion Steering
Power cylinder acts directly within the steering racks main body.
Fluid reservoir can be located on top of belt- driven hydraulic pump.
Control valve within steering rack body connected to top of pinion shaft.
Steering gear mounted to cross-member or frame.
Fluid fed to power cylinder via valves and hoses.
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20. Control valve (inside pinion housing)
Power Rack-and-Pinion Operation
Control valve operates with direction of movement of the pinion gear (steering column).
Rack
Pressure hoses
Power cylinder
Seals
Steering column
Control valve (inside pinion housing)
Control valve directs fluid flow to the correct side of the power cylinder piston.
Piston
Piston moves and assists steering rack movement.
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21. Integral-Piston Power Steering System
Hydraulic pump belt-driven from engine.
Control valve and piston in steering box housing.
Piston inside the steering box assists Drop arm movement.
Idler arm guides lateral movement.
Track rods link to steering knuckles.
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22. Control valve (part of the gear housing)
Integral Power Steering Gear Operation
Some belt-driven pumps have integral reservoir.
Reservoir
Pump
Control valve (part of the gear housing)
Steering wheel stationary - pressure to control valve returned to the reservoir.
Steering wheel to right - control valve moves and feeds pressure to the correct side of the piston to give turning assistance.
Piston
Drop arm
Gear housing
Steering wheel to left - control valve moves and feeds pressure to the other side of the piston, giving turning assistance in the opposite direction.
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23. Question 8 What does the belt of a hydraulic pump connect to?
A) Drop arm
B) Engine
C) Steering column
Correct Answer = B
D) Piston

24. External Cylinder Power Steering
Power cylinder attached to frame via a bracket and to centre link.
Steering gear couples to Drop arm.
Control valve fed from Drop arm.
Standard idler link.
Pump has reservoir on top.
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25. Power Steering Pumps
Many different types of pumps can be used, the most common is the vane type.
Cap and fluid level dipstick
Power steering vane pump component parts.
End plate seal
Belt
Bearing
Pulley
Pump body and centre shaft
Vanes
Vane body
Vane housing
Supply and return hoses
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26. Vane-Type Steering Pump Operation
Vanes throw out into cammed cylinder.
Vanes
Cavity expands near inlets forming vacuum.
Fluid compresses near outlets forcing fluid out.
Low pressure in inlet pipes.
High pressure in outlet pipes.
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