Differentials & Final Drive Assemblies

Question 1

What are 3 purposes of the differential?

Answer 1

rotate power 90 degrees, increase torque, allow tires to turn at different speeds

Question 2

What part does the driveshaft bolt on to?

Answer 2

pinion flange or companion flange

Question 3

What does a salisbury axle have that a banjo doesn’t?

Answer 3

cover

Question 4

What is the name of the part that gets removed from a banjo differential as an assembly?

Answer 4

pumkin

Question 5

Power goes from the case to what component next?

Answer 5

pinion shaft

Question 6

What type of bolts hold the ring gear to the case?

Answer 6

Grade 8 left hand threads bolts

Question 7

What component houses the differential in a FWD vehicle?

Answer 7

transaxle

Question 8

What will determine the type and size of the differential installed in a truck?

Answer 8

transmission, engine, weight, towing, loads & size

Question 9

What are the different types of LSDs?

Answer 9

gear, viscous, electronic, locking, clutch

Question 10

What is an advantage of an LSD over and open differential?

Answer 10

prevents tire slip

Question 11

What type of differential has an internally mounted gear assembly?

Answer 11

Salisbury (integral)

Question 12

What type of differential has removable gear assembly?

Answer 12

Banjo (removable carrier)

Question 13

Describe the power flow of the differential

Answer 13

drive pinion gear -> ring gear -> case -> pinion gears -> side gears -> axle

Question 14

What is a Hypoid Gear?

Answer 14

Teeth are cut on an angle and gears meshes below center line

Question 15

How much pressure can build up between the pinion gear and ring gear?

Answer 15

400,000PSI

Question 16

How often do you change the fluid on an open differential?

Answer 16

50,000 kms

Question 17

How often do you change the fluid on an Limited Slip differential?

Answer 17

25,000 kms

Question 18

What is the max fill on a differential?

Answer 18

half an inch from bottom of fill hole

Question 19

How often can you reuse a crush sleeve?

Answer 19

Just once!

Question 20

How tight should the pinion bearing preload be?

Answer 20

15 - 25 ft.lbs

Question 21

What is a semi floating axle?

Answer 21

Weight of the vehicle goes through the axle bearing

Question 22

What is a full floating axle?

Answer 22

Weight of the vehicle does not go through the axle bearing

Question 23

What is the gear ratio of the final drive called?

Answer 23

axle ratio

Question 24

How do you determine Axle Ratio

Answer 24

divide the number of teeth on the ring gear by the number of teeth on the drive pinion gear

Question 25

What are the characteristics of a Growl Noise? (coming from the Differential)

Answer 25

• low frequency sound
• constant in intensity
• not torque sensitive
• can be heard through all speed ranges.

Question 26

What are the characteristics of a Howl Noise? (coming from the Differential)

Answer 26

• medium frequency sound
• rhythmic oscillation
• can be heard through all speed ranges
• torque sensitive

Question 27

What are the characteristics of a Whine Noise? (coming from the Differential)

Answer 27

• high frequency sound
• no oscillation
• sharp metallic quality
• speed, torque & load sensitive

Question 28

What type of noise would be made with excessive runout of rotating parts on a differential?

Answer 28

Howl Noise

Question 29

What type of noise would be made from a bearing issue in a differential?

Answer 29

Growl Nosie

Question 30

What type of noise would be the result of a ring and pinion gear issue in the differential?

Answer 30

Whine Noise

Question 31

During a differential pinion and ring gear pattern test, what is the condition when the markings on both drive and coast sides are towards the heel?

Answer 31

Pinion Depth is correct & backlash incorrect (to much clearance)

Question 32

During differential pinion and ring gear pattern test, what is the condition when the markings on both drive and coast sides are towards the toe?

Answer 32

Pinion Depth is correct & backlash incorrect (to little clearance)

Question 33

What type of ring gear has the toe and heel equal in size?

Answer 33

Face Hobbed (2-cut)

Question 34

What type of ring gear has the toe shorter then the heel?

Answer 34

Face Milled (5-cut)

Question 35

What design drive pinion uses 3 bearings

Answer 35

Straddled

Question 36

What design drive pinion uses 2 bearings?

Answer 36

Overhung

Question 37

With which type of differential gear set does the pinion gear teeth contact every ring gear tooth?

Answer 37

Hunting Gear Sets

Question 38

What type of differential gear set cannot be reduced any further?

Answer 38

Hunting Gear Set

Question 39

What type of differential gear set end in a whole number?

Answer 39

Non-hunting Gear Set

Question 40

With which type of differential gear set does the pinion gear tooth only contact a few ring gear teeth during each revolution?

Answer 40

Non-hunting Gear Sets

Question 41

With which type of differential gear set does the pinion gear teeth need more then 1 revolution to contact the highest number of ring gear teeth

Answer 41

Partially Non-hunting Gear Sets

Question 42

What type of differential gear set end in .20, .25, .50 or .75?

Answer 42

Partially Non-hunting Gear Set