Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Transmissions > Clutch > Flashcards

Clutch Flashcards

1
Q

Where is the clutch assembly found?

A

Inside the bell housing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the purpose of a clutch?

A

To assist in transmitting the drive of the engine to the road wheels smoothly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the benefits of using a clutch?

A
  • Disconnects power produced by the engine from the gearbox

- Progressively connects power to the gearbox, allowing a smooth take up of drive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the different types of clutch?

A
  • Dog clutch
  • Friction cone clutch
  • Basic friction plate clutch
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is a key feature of a dog clutch?

A

Two mated castellated faces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the major disadvantage of a dog clutch?

A

It is difficult to connect the two castellated faces when the revolutions are high

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a major disadvantage of a friction cone clutch?

A

Heat from friction can cause expansion of the male end inside the female end

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the most common type of main clutch in a vehicle?

A

Friction plate clutch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the parts of a clutch assembly?

A
  • Flywheel
  • Driven plate
  • Pressure plate
  • Release bearing
  • Release arm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the functions of a flywheel?

A
  • Absorb and release kinetic energy during idle strokes
  • Reduce vibration
  • Transmits starter motor power
  • Mounting surface for clutch assembly using dowels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the purpose of a spigot bearing?

A
  • Supports the end of the gearbox input shaft
  • Allows a differential speed between the crankshaft and gearbox input shaft
  • Allows the input shaft to slow down when the clutch is operated whilst the engines running
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What types of spigot bearing are there?

A
  • Ball type bearing

- Phosphor bronze type

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What type of fit are spigot bearings?

A

Interference fit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why are ball type spigot bearings sealed for life?

A

To prevent grease escaping and frequent difficult maintenance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the driven plate also known as?

A

Friction plate or centre plate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What faults could occur if a plan steel plate with friction material attached to each side was used?

A
  • Buckling of the plate due to hear which could cause drag
    (Drag is the plate rubbing against flywheel/pressure plate even though the clutch pedal is fully down)
  • Small movement of the pedal between engagement and release of the clutch can cause erratic/harsh drive take up
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Why must you wear PPE when dealing with friction plates?

A

They may contain asbestos

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What feature is used on a friction plate to prevent buckling?

A

Slots to allow a flexing action

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the purpose of alternately fixed riveting on a friction plate?

A

To give a wavy profile called ‘borglite crimping’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the purpose of borglite crimping?

A

Helps the lining spring apart when the clutch is disengaged to prevent clutch drag

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What effects does increasing the axial compression on a driven plate have?

A
  • Spreads engagement over a greater range of pedal movement, allowing a smoother engagement of drive
  • Increases airflow between segments and friction surfaces, enhancing heat dissipation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the purpose of large slots in the inner hub of a clutch?

A

To accommodate damper springs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the purpose of damper springs?

A
  • Transmit drive

- Absorb torsional shocks during drive engagement, from engine vibrations and during overrun

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is overrun?

A

When the wheels are driving the gearbox, rather than the gearbox driving the wheels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are the functions of the pressure plate?

A
  • To provide a flat face that mates with the friction plate

- To provide a clamping force on to the friction plate to transmit drive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the two basic designs of pressure plate assemblies?

A
  • Diaphragm spring

- Multi-coil spring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are advantages of a diaphragm spring?

A
  • Compact and lightweight
  • Less moving parts
  • Suitable for high engine speeds because:
    Not affected by centrifugal force
    No vibrations due to spring imbalance
  • Lower pedal force is required to release clamping pressure
  • Clamping force does not reduce as friction linings wear
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are the purpose of drive straps?

A

To transmit drive from the cover to the pressure plate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What shapes do the diaphragm spring alter from during operation?

A

From convex to concave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the purpose of a fulcrum ring?

A

To act as a lever to cause the diaphragm spring to change shape as oppose to move

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What are drive straps made of?

A

Spring steel

32
Q

What are disadvantages of a multi-coil spring?

A
  • Bulky and expensive to manufacture
  • Prone to centrifugal effects
  • Large pedal force required
  • Clamping force decreases as friction linings wear
33
Q

What are the parts of a multi coil spring pressure plate?

A
  • Pressure plate casting
  • Pressed steel cover
  • Coil springs (avg 16)
  • Release lever (3 or more)
  • Eye bolt assembly (each one has 3 components)
  • Anti-rattle springs (same amount as levers)
  • Thrust ring (if fitted)
34
Q

What is the purpose of a knife edge in a release lever?

A
  • Acts as a double pivot point between the release lever and the pressure plate
  • Ensures the pressure plate moves squarely in relation to the centre plate
35
Q

What are the purpose of the anti rattle springs?

A

Springs are placed to ensure the release lever is held in the correct position and reduces unwanted noise

36
Q

What creates the clamping force in a multi-coil spring plate?

A

The springs

37
Q

What 3 parts make up the release lever assembly?

A
  • Eye bolt
  • Release lever (toggle lever)
  • Knife edge
38
Q

What determines how much torque can be transmitted by a plate-type clutch?

A
  • Size of the clutch (radius)
  • Pressure applied by the pressure plate
  • Area of contact for the centre plate
39
Q

What are the 2 main types of multi plate clutch?

A
  • Dry

- Wet

40
Q

What components make up a wet multi plate clutch?

A
  • Clutch cover
  • Inner hub (inc. primary shaft)
  • Outer plates
  • Inner plates
  • Withdrawal sleeve
  • Thrust springs
41
Q

What two designs of wet clutch cover are there?

A

One or two piece pressed steel

42
Q

What feature on a wet clutch inner plate allows for easier separation?

A

They are slightly dished

43
Q

What replaces a release bearing in a wet clutch?

A

A withdrawal sleeve

44
Q

Can you service a release bearing?

A

No

45
Q

What two types of release bearing are there?

A
  • Enclosed ball race bearing

- Solid bonded carbon pad

46
Q

What is a release arm also known as?

A

Clutch fork

47
Q

What two types of material are clutch forks made of and why?

A
  • Pressed steel: Light to medium duty

- Drop forged steel: Heavy duty

48
Q

What is FPM?

A

Free pedal movement, the movement in the clutch pedal before drive is disengaged

49
Q

How do we adjust free pedal movement?

A

At the pushrod

50
Q

What are the two main reasons for FPM?

A
  • To keep release bearing clear of the pressure plate to prevent premature wear
  • To ensure full spring pressure acts on the pressure plate when drive is engaged
51
Q

What 2 methods of clutch operating mechanisms are there?

A
  • Mechanical (cable or rod)

- Hydraulic

52
Q

What type of automatic cable adjustment is there?

A

Quadrant and pawl

53
Q

How is assistance provided to operate the clutch in heavy vehicles?

A

Clutch (air) servo

54
Q

In a clutch air servo, what component seals the air inlet when the clutch pedal is released?

A

Reaction Plunger

55
Q

What component seals the exhaust valve when the clutch pedal is pressed?

A

Reaction member

56
Q

What are the 5 main faults that can cause in the clutch assembly?

A
  • Slip
  • Drag
  • Judder
  • Fierceness
  • Bearing noise
57
Q

What are the symptoms of clutch slip?

A
  • Rev increase without vehicle speed increasing
  • Smell of burning friction material
  • In severe cases the vehicle will not drive up steep hills
58
Q

What can cause clutch slip?

A
  • Insufficient free pedal movement
  • Worn clutch driven plate facings
  • Partial seizure of pedal linkage/hydraulic cylinder
  • Defective/partially seized pressure plate
  • Oil contaminated clutch facings
  • Fouling of the pedal preventing full return
59
Q

What are the symptoms of clutch drag?

A
  • Difficulty in engaging 1st or reverse gear from neutral
  • Vehicle jolts when changing gear with vehicle in motion
  • May continue to move when the clutch pedal is fully depressed
60
Q

What are possible causes of clutch drag?

A
  • Excessive FPM (incorrect adjustment or lack of hydraulic fluid or air in the system)
  • Fouling/wear of linkage preventing pedal being fully depressed
  • Oil-contaminated facings causing one to stick to a driving surface
  • Defective driven plate or seizure on splines
  • Misalignment of friction faces
  • Partially seized or collapsed spigot bearing
61
Q

What are the symptoms of clutch judder?

A

A severe, low frequency vibration wen the clutch is released while vehicle is moving from stationary

62
Q

What are the possible causes of clutch judder?

A
  • Jerky pedal - Sticking cable or pivot point
  • Excessive engine movement during take up of drive because of defective: Tie rod, drive line, suspension
  • Oil-contaminated facings
  • Defective pressure plate
  • Misalignment of friction faces
  • Defective driven plate
  • Defective diaphragm spring causing an imbalance
63
Q

What is the symptoms of clutch fierceness?

A

Sudden engagement of the clutch, even though its being gradually released

64
Q

What are possible causes of clutch fierceness?

A

Any defect that allows clutch take-up to be faster than the movement of the pedal, including: Partial seizure of the pedal linkage, contamination of hydraulic fluid

  • Driven/centre plate contamination
  • Misalignment of friction faces
65
Q

What are the symptoms of bearing noise?

A
  • A rumbling or squealing when the clutch is pressed

- Noise disappears when clutch is released

66
Q

What are the possible causes of bearing noise?

A
  • Defect in the release bearing, including: Dry bearing, seized bearing, fair wear and tear
  • Excessive bearing wear caused by incorrect clutch FPM
  • Partially seized linkage
67
Q

What type of clutch do automatic gearboxes use?

A

Fluid clutches

68
Q

What are the two main types of fluid clutch assembly?

A
  • Fluid flywheel

- Torque converter

69
Q

What is a disadvantage of a fluid flywheel?

A

Slip cannot be completely eliminated

70
Q

What is the purpose of the stator in a torque converter?

A

To increase the speed of the turbine

71
Q

What are the 3 main differences between a torque converter and a fluid flywheel?

A
  • Contains a stator
  • Vanes are angled
  • 2 flow control rings
72
Q

Where is the stator in a torque converter?

A

Mounted on a one way clutch

73
Q

What is the stator also known as in a torque converter?

A

A reaction member

74
Q

What is the purpose of the lock up clutch?

A

To keep the impeller and the turbine together to spin at the same speeds

75
Q

What type of one way clutch is in a torque converter?

A

Sprag type

76
Q

What is maintenance of a torque converter limited to?

A
  • Oil change (gearbox oil)
  • Replacement of oil seals (on gearbox)
  • Check with associated publication (AESP or AP) for any further maintenance

Transmissions (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions