Driveline Fundamentals and Service

Question 1

Identify three functions of a driveline assembly.

Answer 1

a. Provides a means of transmitting power.
b. Allows angle changes to occur in the path or power.
c. Allows length changes to occur in the driveline.

Question 2

When two driveline assemblies are used on a vehicle with a long wheelbase, what type of bearing must also be used on that type of driveline arrangement?

Answer 2

Center support bearing, aka midship bearing

Question 3

Explain what safety precautions should be taken when stationary engines are using any sort of driveline to transmit power to a pump or other device.

Answer 3

Use suitable guards around the driveline components. Do not work on moving driveline components.

Question 4

When a new driveline tube is installed, the overall driveline length should be the same as the old one. What are two other checks/adjustments that should also be done to the rebuilt driveline assembly before installation?

Answer 4

a. Run out checks (compare to specifications)

b. Balancing of the assembly (within allowable limits)

Question 5

Identify the two types of driveline arrangements used to enable each pair of universal joints to have equal working angles.

Answer 5

a. Parallel arrangement.

b. Broken- back or intersecting angle arrangement.

Question 6

Which device allows a driveline to change in length during operation?

a. full round yoke.
b. universal joint.
c. half round yoke.
d. slip joint.

Answer 6

d. Slip joint.

Question 7

When replacing a universal joint you notice the trunnions have false brinelling. After replacing the universal joint, which of the following is the desired universal joint working angle to ensure proper lubrication?

a. 0
b. 0.25
c. 0.5
d. 1

Answer 7

d. 1

Question 8

A driveline is said to be in phase if the centerlines of the two yokes on that driveline are in line with each other, when viewed down the length of the driveline.
True
False

Answer 8

True

Question 9

A balanced driveline vibration should be eliminated if the universal joint working angles are equal, or at a difference of no more than one degree.
True
False

Answer 9

True

Question 10

A driveline may have to be offset to one side. the universal joint working angles must be calculated with the offset measurement taken into account.
True
False

Answer 10

True

Question 11

Universal joint working angles are not affected by driveline speed.
True
False

Answer 11

False

Question 12

A basic driveline configuration has one shaft. Mor complex driveline configurations use:

Answer 12

C. Multiple shafts

Question 13

Explain how a multiple shaft driveline arrangement can work without using a center support bearing.

Answer 13

The vehicle could be equipped with a tandem rear axle assembly or an axillary transmission. This shortens the distance between major components and eliminates the need for a center support bearing.

Question 14

Identify the two common types of damage that can be sustained by a driveline tube.

Answer 14

a. bents (due to impact)
b. twists (due to overloading and shock loads)
c. impact from objects
d. contact with the terrain.

Question 15

Identify possible driveline problems that may arise if a vehicle wheelbase is lengthened.

Answer 15

The old driveline may need to be retubed for the new length. If the distance is too great, a multiple shaft arrangement may need to be fabricated. A center support bearing may be required.

Question 16

When installing a universal joint, the grease fitting can point toward the shaft or away from the shaft since the direction it faces is not important.
True
False

Answer 16

False.

Question 17

Explain the purpose of the center support bearing.

Answer 17

It supports the weight of one shaft in a multiple shaft driveline and accurately positions one shaft in relation to another shaft.

Question 18

When the bearing straps are used, new retaining caps screws coated with a self locking compound should be used when installing universal joint bearing cups.
True
False

Answer 18

True

Question 19

Driving phasing can be checked with a bubble level or an inclinometer marked in degrees. Explain the procedure used to check phasing with these types of instruments.

Answer 19

Place the bubble level on one universal joint yoke at 90 degress to the shaft. Slowly rotate the shaft until bubble indicator indicates Without turning the bubble level, move it to the yoke at the other end of the driveline. Read the level scale. If the reading is zero, the driveline universal joints are in phase.

Question 20

When checking the universal joint working angles, a bubble level with a degree scale can be used. Explain how you would check the working angle of one universal joint using this type of measuring instrument.

Answer 20

Position the level on a machined surface on the transmission, or on the vertical output shaft, to determine the angle at which it was sloped. If the transmission is sloped down, note this as a positive degree reading. Position the level, facing the same direction, on a cleaned portion of the driveshaft, about halfway down the shaft. If the shaft is also sloped down, note this as a positive degree reading.

If both readings are the same, either both positive (down slope) or both negative (up slope), subtract on from the other to calculate the working angle of that universal joint. If both readings are different, one negative and one positive, add the readings to calculate the working angle.

Question 21

When determining compound drive line angles, explain how to calculate the true universal joint working angle.

Answer 21

First, measure the universal joint working angle from the side view (vertical axis.) Then, calculate the universal joint working from the top view (horizontal plane) by measuring the length of the driveline (measurement A) and the distance between the center line of the two corresponding yokes (measurement B). Input the values into the chart to determine the horizontal driveline angle. Then, take the two values and enter them into the formula. C degrees= squareroot of (t squared plus s squared) and calculate.