HET 4 DRIVELINE

Question 1

Why is correct phasing of a driveline important?

Answer 1

Vibration free driveline

Question 2

What tool is used to check for phasing?

Answer 2

inclinometer or bubble level

Question 3

How accurate are inclinometers?

Answer 3

1/4 degree

Question 4

What is the minimum degree needed for lubrication in a driveline?

Answer 4

1°

Question 5

What is the preferred angle for lubrication of the driveline?

Answer 5

high driveline angle

Question 6

When taking a bubble level scale reading from one u-joint yoke to the next, what condition is the driveline in if the readings are not 0 on both?

Answer 6

Tube could be twisted

Slip joint assembled incorrectly

Question 7

What do the readings on the bubble scale level mean if they are zero on both universal joint yokes on the driveline?

Answer 7

Driveline is in PHASE

Question 8

If the slip joint is installed 180° out of alignment, what would the phasing and balance be of the driveline?

Answer 8

Phasing would look correct but the balance would be out

Question 9

If a driveshaft is angled down what type of degree does it have? (positive, zero or negative)

Answer 9

Positive dregree

Question 10

If a driveshaft is level what degree does it have?

positive, zero or negative

Answer 10

Zero degree

Question 11

Where should your inclinometer be placed when checking for phasing?

Answer 11

on a machined surface

the yoke is usually cast and might not be a good surface to take a reading from

Question 12

When taking a reading on the driveline with a bubble level gauge, is it okay to move it any which way while switching which u-joint is being measured?

Answer 12

NO, same direction same way from each point

Question 13

Why is driveline phase and yokes being parallel to each other important?

Answer 13

so no vibration is created and u-joints are able to spread lube

Question 14

When measuring driveline, at what end of the vehicle should you start at?

Answer 14

the front of the vehicle (transmission output shaft)

Question 15

If both readings of the angle of the driveshaft u-joint are positive, what should be done to the reading to find the working angle?

Answer 15

Subtract them from eachother

Question 16

If one shaft u-joint slopes up and the other slopes down, what must be done to the angles to find the working angle?

Answer 16

Add them together

Question 17

When are multiple drive shafts used?

Answer 17

Tandem Rear Axle
Long wheel base
Aux transmission - more gear selections

Question 18

True or False?

Seals can handle and support the weight of the driveshaft?

Answer 18

FALSE

Question 19

What should be done with exposed driveshafts, above the frame of the vehicle, in regards to safety?

Answer 19

Guards, shields

Question 20

On a long single driveshaft what should be used to help support the load?

Answer 20

Midship bearing, steady bearing or center support

Question 21

On what type of vehicles are single driveshafts used on?

Answer 21

Short-wheel based vehicles

Question 22

Midship bearings are generally sealed or serviceable?

Answer 22

Sealed

Question 23

What is the purpose of a slip joint on a driveshaft?

Answer 23

To handle change in length, caused by suspension travel

Question 24

What is the basic purpose of the drivetrain?

Answer 24

To transmit power from the Drive member to the Driven member

Question 25

What dictates the allowable limits in a drivetrain?

Answer 25

Manufacture spec, service manual

Question 26

What can cause damage to the driveline tube?

Answer 26

Impacts from terrain, overloaded, high torque load

Question 27

A bent/damaged driveline tube can be cause what symptom?

Answer 27

Vibration

Question 28

To true the balance of a driveshaft what can be done?

Answer 28

Weights can be added to balance the driveshaft

Question 29

Is it every allowable to have a driveshaft out by one tooth, in regards to phase?

Answer 29

Yes, engineered design - heavy torque loads

Question 30

Is runout important on a driveline?

Answer 30

Yes, there very specific allowances for runout

Question 31

Is the driveline balanced with or without both universal joins?

Answer 31

With u-joints

Question 32

How are balancing weights mounted to the driveline?

Answer 32

Welded on

Question 33

Why do drivelines have speed ratings?

Answer 33

The max speed rating is what the driveline has been trued to on special machines

Question 34

Describe a trunnion on a u-joint?

Answer 34

Highly polished bearing surface, located at the end of each u-joint cross arm

Question 35

What is required on the bearing strap retaining fasteners?

Answer 35

Locking compound - manufacture spec

Question 36

What is inside the bearing cap of a u-joint?

Answer 36

Specific number of precision-ground needle bearings

Question 37

Why is greasing all four bearings caps/trunnions important on a driveline u-joints?

Answer 37

If any bearing cap is not receiving grease will fail prematurely

Question 38

The small amount of play between internal and external splines on a driveline are for what?

Answer 38

To allow grease/lube to get in between them

Question 39

If a driveline is well lubes and the slip joint has play up and down AND side to side, what condition is the slip joint in?

Answer 39

Failed, worn out

Question 40

If a slip joint is worn out what could be the operators complaint?

Answer 40

Vibration

Question 41

What are the three versions of Yokes?

Answer 41

Half round Full round Wing style

Question 42

What kind of fit should the cap and yoke bore have?

Answer 42

Interference fit

Question 43

What is most likely to be used with a centre support bearing?

Answer 43

Shims

Question 44

What is the maximum difference allowed in a parallel shaft arrangement?

Answer 44

1°

Question 45

What is the other name for a broken-back driveline arrangement?

Answer 45

intersecting angle

Question 46

What should be done before a visual inspection of driveline components?

Answer 46

Clean the area

Question 47

What types of damage can be seen on the splines of a split joint?

Answer 47

Twisted Galling Excessive movement/play

Question 48

A slip joint has too much play in the splines, what would be the complaint?

Answer 48

Vibration

Question 49

If a slip join has too much clearance in the splines what may have a premature failure?

Answer 49

U-joints

Question 50

What are some signs of lack of lubrication in a driveline?

Answer 50

False brinelling Rust Galling

Question 51

What can cause pitting in a u-joint?

Answer 51

Contaminated lubricant

Question 52

How should yoke bores and u-joint bearing surfaces be cleaned?

Answer 52

fine emery cloth

Question 53

What should technicians be aware of when removing u-joints?

Answer 53

The caps will become loose once the cross is removed, secure the caps to the trunnions

Question 54

Should u-joints be greased before or after install?

Answer 54

After

Question 55

Why is it important to install u-joints the correct way, with a press?

Answer 55

Brinelling can be caused by a bad install

Question 56

Driveline vibrations can be caused by a multitude of problems, what are some questions that should be asked before trying to find the fault?

Answer 56

When did the vibration start? Was it gradual or sudden? Were you loaded or empty? What were the road conditions? At what speed and RPM did it occur? Did it happen during acceleration or deceleration? Has the suspension or wheel base changed recently?

Question 57

What are the 5 steps to diagnose a driveline vibration?

Answer 57

``` Gather Info Road Test Simulate Conditions Record Findings Stationary Inspection ```

Question 58

Who is the best person to check for the balance of a driveshaft?

Answer 58

A specialized driveshaft shop

Question 59

Stationary test of driveline are done in what position in the transmission?

Answer 59

Neutral

Question 60

What speeds should be gone through in a stationary test?

Answer 60

Idle to governed speed

Question 61

If a vehicle has a long wheelbase and multiple driveshafts, do you have to use midship bearings or is there another way to support the system?

Answer 61

To NOT use midship bearings, there would have to be multiple rear axles and/or auxiliary transmission, it would shorted then shafts helping with the weight

Question 62

For on-road application what is generally the largest allowable working angle in the drivetrain?

Answer 62

3°

Question 63

A brokeback drivetrain system has a positive angle of 3° at one end and a negative angle of 3° at the other end, what is the result?

Answer 63

They zero each other out

Question 64

What are the two ways to secure a yoke to a driveshaft tube?

Answer 64

Welded or slip (sleeve) that spline to the stub tube

Question 65

What are the arrows on a different parts of the driveline for?

Answer 65

To align the driveshaft - proper phasing

Question 66

How are the ends of a driveshaft tube mounted (stub shaft or tube yoke)?

Answer 66

Welded

Question 67

What does Air Ride Suspension do to our driveline angles?

Answer 67

Tries to keep the angle constant

Question 68

If a vehicle does not have air ride suspension, what could happen to the driveline angles as the vehicle is loaded and unloaded?

Answer 68

Angles will change with weight

Question 69

When removing drivelines, you should always follow all safety precautions. What should a technician be aware of when removing a driveline?

Answer 69

Non-destructive marking for alignment

Question 70

What types of u-joints eliminate pulsation in the driveshaft?

Answer 70

CV, double cardan, double universal

Question 71

What is the first visual indication of worn u-joints?

Answer 71

RUST

Question 72

What is used to connect a driveline at two components?

Answer 72

2 universal joints - parallel

Question 73

What type of driveline yokes are most commonly used in heavy equipment (off-road)?

Answer 73

Wing type

Question 74

What type of driveline yokes are used in heavy truck (on-road)?

Answer 74

Full or Half round yokes

Question 75

What can cause universal trunnions to have end galling?

Answer 75

Lack of lube or high working angle

Question 76

What attaches two yokes together?

Answer 76

U joints

Question 77

Why are alignment marks important on drivelines?

Answer 77

Manufacture spec may have the driveline out of phase

Question 78

How many bearing caps mount to a yoke?

Answer 78

2