Crucial Transmission Points Flashcards
What would excessive free play in the clutch cause?
Clutch drag
What would insufficient free play in the clutch cause?
Clutch slip
What is the most likely fault if the clutch emits a constant bearing whine, when the clutch is not depressed?
A worn clutch release bearing
Which of the following components is not part of the clutch release mechanism:
Clutch pedal
Pressure plate
Clutch cable
Centre plate
Centre plate
What is the purpose of the sliding joint fitted to as prop shaft?
To accomodate for changes in the propellor shaft length due to movement
Why is a customer’s signature required to authorise work being carried out on a vehicle?
It creates a legally binding contract between the customer and the garage
What type of gears are used in a sliding mesh gearbox?
Spur gears
Which fault can cause clutch slip?
Lack of free play
What should be done to safeguard yourself and others when working in a vehicle repair workshop?
Adhere to all the above
Why are multi-plate clutches used
When there is not much space and a high torque needs to be transmitted
Which of the following is not a legal requirement when test-driving a vehicle on a public road:
A current road fund license
Driver wearing a seat belt
Trade plates front and rear
A valid driver’s license
Trade plates front and rear
Why should you report any defects when carrying out a routine service on a vehicle?
So the customer can be contacted to get their authority to do extra work
What is the most likely cause of difficulty engaging gears, especially in 1st?
Clutch drag
What can a misaligned propeller shaft in a rear wheel drive car cause?
Transmission vibration
An automatic gearbox usually contains a…
Sun gear, planet gear and annulus/ring gear
What dooes a front wheel drive transmission use?
Constant velocity joints
List 5 components of the clutch release mechanism
Master cylinder, slave cylinder, hydraulic lines, clutch pedal, clutch fork
What would the effect of air in the clutch hydraulic operating system be?
The clutch being unable to fully disengage, because hydraulic transmission relies on compression of liquid and air can be compressed, reducing pressure
Give a symptom of clutch slip
Revs increase bu the car does not accelerate
Give a symptom of clutch drag
Difficulty shifting gears
Give a symptom of clutch judder
Jarring vibration in the steering wheel
Name the clutch component that drives the gearbox
The clutch plate
What does the clutch interlock mechanism do?
Prevents 2 gears from being selected simultaneously
How are gears connected to the output shaft on a 4-speed constant mesh gearbox?
Using needle roller bearings
What will a worn synchro cone/baulk ring result in?
Crashing into gear
Define hypoid axle
A kind of rear axle where the pinion engages the crown wheel below the centre line
What would a typical final drive ratio be?
Between 3:1 and 4:1
Where can a fully floating axle be found?
On light HGVs
In a vehicle with a fully floating rear axle, what will a broken axle cause?
The wheel will not fall off
List 3 advantages of using a diaphragm spring clutch over a multi coil spring clutch
Smaller in size and weight, transfers more torque, higher load-carrying capacity
List 2 reasons to use a clutch centre plate with a spring hub
Reduces torsional stress, absorbs shock loads from sudden clutch engagement
What is the difference of the transmission ratios in a rear wheel drive car, compared to front wheel drive?
There is only one transmission ratio, because it’s just input to output shaft, no lay shaft
Why does the baulk ring/synchro cone have a screw type finish on its surface?
To let oil escape
What kind of oil should be used in a rear wheel drive final assembly?
EP (extreme pressure) oil
What substance is used to lubricate the wheel bearings in a car?
LM grease (might just say grease)
The gear ratio is 2:1. If the engine sends 120 Nm of torque at 5000 rpm into the input shaft, what will the gearbox send into the output shaft?
240 Nm at 2500 rpm
Where does the half shaft transmit drive from?
Propellor shaft to the gearbox universal joints
The clutch fork actuator system may be a direct mechanical system or…
Hydraulic
When calculating the gear ratio on a gear set that incorporates the idler gear…
Ignore the idler gear size, focus on driver and driven
What’s another term for gear reduction?
Underdrive
How does a coil spring clutch look different do a diaphragm spring clutch?
The springs come outward
The gear ratio is 2:1. What will happen?
Torque will be double the input.
Speed will be half the input
A better term for longituadinal driveline?
Transverse
What tool do you use to remove the inner track of a bearing?
Puller
What’s the prop shaft made of?
Steel
What vehicle will a fully floating axle be used on?
Light HGVs
Which 2 transmission components are inspected in an MOT test?
The CV joint and boot
Why would you use a DTI on a final drive assembly?
To check backlash
When is clutch drag more noticeable?
In 1st and reverse gear
What does the detent do?
Holds the selector shaft in place
Which clutch component drives the gearbox?
Clutch plate
Name one symptom of clutch slip
Revs go up, without accelerating
A visual inspection of the clutch release assembly will reveal…
Surface cracks and hotspots
What is the purpose of the synchronisers?
Ensure that the gears rotate at the same speed, to prevent gear clash
What fault is most likely to produce clutch judder?
Sticking clutch cable
What is the most likely cause of a load knocking sound while turning in front-wheel drive?
A badly worn constant velocity joint
What can a badly worn gear change mechanism result in?
Difficulty changing gears
What will a rear crankshaft oil seal leaking result in?
Clutch slip
Which of these will result in failing an MOT test:
An outer constant velocity joint gaiter is split
What happens if the interlock mechanism is defective?
Transmission would lock up, causing damage
