Independant Suspension

Question 1

What are the disadvantages of beam axles?

Answer 1

Axle movement is limited

Camber angle is altered if one wheel hits a bump causing shimmy

Deflection of the leaf spring alters castor angle

High un-sprung weight

Question 2

What is independent suspension?

Answer 2

Overcomes all the disadvantages of solid beam axles

Any system that connects the wheels to the frame , one wheel has no effect on the other

Question 3

Three common types of IFS?

Answer 3

Double wishbone

Double link and radius rod

MacPherson strut

Question 4

What type of suspension do double wishbone and double link use?

Answer 4

Leaf, coil and torsion

Question 5

What construction does McPherson use?

Answer 5

Coil springs

Question 6

What are the advantages of IFS?

Answer 6

Improved ride comfort

Better road holding

More accurate steering

Reduced steering wobble

Increased passenger space

Question 7

What does the shape of the wishbone provide?

Answer 7

Provides stiffness resisting breaking torque

Question 8

How many bearings do each wishbone have?

Answer 8

3

Question 9

How can the diving of the wishbone be prevented when brakes are applied?

Answer 9

By placing the rear pivot point of the lower wishbone higher than the front pivot point

Question 10

How is castor angle maintained?

Answer 10

By mounting the top of the wishbone slightly behind the lower wishbone

Question 11

What type of load can double link and radius rod not take?

Answer 11

Longitudinal dynamic loads and braking torques

Question 12

What can overcome the disadvantage of the double link and radius rod?

Answer 12

By a semi-trailing radius rod which is fitted in between the lower link and the frame

Question 13

What type of tube is incorporated in the MacPherson?

Answer 13

Long telescopic tube with the damper

Question 14

How is the MacPherson pivoted?

Answer 14

By a bearing at the top

Question 15

How is the track control maintained?

Answer 15

By a single transverse link also know as a track control arm

Question 16

How is the MacPherson connected to the stub axle?

Answer 16

Ball joint

Question 17

When are the castor and camber angles set?

Answer 17

During production

Question 18

What is a common means of attachment?

Answer 18

Ball joint

Question 19

Why can’t you use a one piece track rod on a IFS?

Answer 19

Wheel alignment would altered if one wheel was deflected up or down

Question 20

How can you overcome the problem of misalignment when using a one piece track rod?

Answer 20

Stub axle moves in an arc, track rod also needs to move in a similar motion

Therefore a three piece track rod is used

Question 21

What are the 2 three piece track rod layouts?

Answer 21

Steering box and rack and pinion

Question 22

What are the advantages of IRS?

Answer 22

Improved ride comfort

Improved traction on rear wheels , due to lack of torsional movement

Vehicle handling is enhanced

Question 23

How can springing be provided ?

Answer 23

Torsion bar connected to the lower wishbone

Coil springs between wishbone and body

Question 24

How is drive transmitted?

Answer 24

From the final drive to angle universal joints

Question 25

When are eccentric cams or shims fitted to each suspension?

Answer 25

To alter wheel alignment