401B: Driveline Fundamentals & Service

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

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

Answer 3

1°

Question 4

If a driveshaft is angled down from the front to back, what type of angle does it have?

Answer 4

Positive angle

Question 5

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 5

Subtract them from eachother

Question 6

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 6

Add them together

Question 7

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

Answer 7

Use guards or shields

Question 8

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

Answer 8

Midship bearing, steady bearing, or center support bearing

Question 9

Are midship bearings generally either sealed or serviceable?

Answer 9

Sealed

Question 10

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

Answer 10

To allow for change in length, caused by suspension travel

Question 11

What is the basic purpose of the drivetrain?

Answer 11

To transmit power from the drive member to the driven member

Question 12

What can cause damage to the driveline tube?

Answer 12

• Impacts from terrain
• Overloaded
• High torque load

Question 13

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

Answer 13

Vibration

Question 14

Durring the manufacturing process, is the driveline balanced with or without both universal joins installed?

Answer 14

With u-joints installed

Question 15

Describe a trunnion on a u-joint?

Answer 15

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

Question 16

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

Answer 16

If any bearing cap is not receiving grease, it will fail prematurely

Question 17

What is the small amount of play between internal and external splines on a driveline for?

Answer 17

To allow grease to get in between them

Question 18

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

Answer 18

Failed, worn out

Question 19

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

Answer 19

Vibration

Question 20

What are the three versions of Yokes?

Answer 20

• Half round
• Full round
• Wing style

401B Pg. 12

Question 21

What is another name for a broken-back driveline arrangement?

Answer 21

Intersecting angle

Question 22

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

Answer 22

Twisted
Galling
Excessive movement/play

Question 23

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

Answer 23

False brinelling
Rust
Galling

Question 24

What can cause pitting in a u-joint?

Answer 24

Contaminated lubricant

Question 25

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

Answer 25

A specialized driveshaft shop

Question 26

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

Answer 26

Neutral

Question 27

What speeds should be gone through in a stationary test?

Answer 27

Idle to governed speed

Question 28

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

Answer 28

3°

Question 29

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 29

Zero degree working angle

Question 30

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

Answer 30

RUST

Question 31

What can cause universal trunnions to have end galling?

Answer 31

Lack of lube or high working angle

Question 32

What is generaly considered to be the maximum length of a single driveshaft?

Answer 32

72"

Question 33

What are common causes of the following u-joint trunnion wear: Spalling End Galling False Brinelling Pitting

Answer 33

Spalling: Heavy loads End Galling: Lack of grease, too high orking angle False Brinelling: Too low working angle, lack of grease Pitting: Contamination ## Footnote 401B Pg. 23