Driveline Differentials and Final Drives

The main drawback of a single universal joint is that:

They cannot transmit torque properly

They require constant lubrication

The drive shaft sections are too long

They do not transfer uniform rotating speed

Correct! Wrong!

Universal joints are "phased" to:

Reduce the twisting action of the propeller shaft

Cancel torsional vibrations

Simplify assembly of the sections to each other

Allow the shaft to change length when the suspension moves

Correct! Wrong!

Some slip joints are coated with a nylon compound to:

Reduce lubrication requirements

Keep dirt and contaminants out

Help keep grease in

Make them slip easier

Correct! Wrong!

The two most significant factors in reducing drive line failure is:

Regular maintenance and careful use

Frequent parts replacement and proper loading

Proper lubrication and correct alignment

Operator training and frequent inspection

Correct! Wrong!

To check a driveline assemble for run-out, you must perform dial indicator tests at three different locations on:

The transmission output flange

The carrier flange

The wheel hubs

The drive shaft

Correct! Wrong!

The prime function of a drive line is to:

Provide extra unsprung weight for the equipment

Transmit torque at a uniform speed

Allow an increase in the distance between units

Provide a method of connecting power take-off units

Correct! Wrong!

One of the first signs of drive line trouble is usually:

Loss of power

Vibration

Difficult shifting

Poor clutch engagement

Correct! Wrong!

A constant velocity joint eliminates the:

Need to balance the driveshaft

Need for a steady bearing

Speed variation caused by U-joint action

Phasing

Correct! Wrong!

On a single shaft with parallel driveline alignment if the transmission is at +3 deg. the front differential should be at:

+3 deg.

-3 deg.

+6 deg.

-6 deg.

Correct! Wrong!

A differential drive axle which does NOT support load and only supplies torque to drive the wheel is called:

A full floating axle

A split axle

A semi-floating axle

A tandem axle

Correct! Wrong!

A differential drive axle which does support load and supplies torque to drive the wheel is called:

A full floating axle

A dead axle

A tandem axle

A semi-floating axle

Correct! Wrong!

Power transmission through the differential until when the vehicle travels straight ahead is, from the pinion through the ring gear and from the casehalf to the:

Differential housing to the axles

Pinion gear to drive the axles

Cross, into the spider gears and sidegears

Differential and crossdrive to the axles

Correct! Wrong!

To ensure proper lubrication of the interaxle differential, some large carriers assemblies use:

Internal oil pumps and filters

An input shaft spline drive

Lower bearing mountings

Higher fluid levels than normal differentials

Correct! Wrong!

The simplest type of wheel traction equalization is the:

Power divider

Proportional differential

Differential lock

Multi-clutch equalizer

Correct! Wrong!

If the operators were to pay attention, one of the first symptoms noticed of pending carrier trouble would be:

Increased operating temperature

Loss of torque

Erratic operation

Excessive metal particles

Correct! Wrong!

Gear tooth fracture is frequently caused by:

Poor lubrication

Improper tooth contact

Shock load

Overheating

Correct! Wrong!

Numbers etched on the pinion gear indicate: 1. set number. 2. tolerance of the gear set and 3. ___________________________.

Model number and year of equipment

Preload on the bearings

Clearance between gears

Pinion depth

Correct! Wrong!

Excessive toe adjustment on the drive side the pinion gear to the driven side of the ring gear will require _________________________.

A decrease in backlash

An increase in backlash

An increase in pinion depth

A decrease in pinion depth

Correct! Wrong!

A differential shows spalling on the teeth of the crown gear, while the gear teeth of the pinion have no signs of wear. What should the technician do?

Replace the ring gear and pinion

Replace the ring gear

Properly rinse out the differential housing and switch to a higher viscosity of lubricant

Correctly adjust the ring gear and pinion backlash before any further damage takes place

Correct! Wrong!

You are setting the correct thrust screw clearance, on a carrier assembly that has a thrust block. Technician A says that on this particular unit, you turn the thrust screw until it stops against the ring gear or thrust block, then tighten one-half turn, and lock the jam nut. Technician B says that on this particular unit, you turn the thrust screw until it stops against the ring gear or thrust block, then loosen one-half turn, and lock the jam nut. Who is right?

A only

B only

Both A and B

Neither A or B

Correct! Wrong!

A technician is measuring pinion to crown backlash with a dial indicator. After following the proper procedure, the dial indicator reads "0" backlash. What should the technician do next?

Alternately loosening and re-tightening bearing adjusting rings until backlash is correct

Continue with assembly; the preload and backlash setting is correct

Tighten one bearing adjusting ring one notch and then loosen the other one notch and re-measure

Adjust the bearing preload and backlash on the other side of the differential

Correct! Wrong!

If the backlash measurement for the ring gear is out of specifications, how can the backlash measurement be brought into tolerance?

Reset the differential side bearings

Remove the ring gear and rotate the part 90 degrees, then reinstall it onto the differential cage

Place a shim between the ring gear and the differential case

Place a shim behind the thrust washers of the differential side pinion gears

Correct! Wrong!

A technician notices excessive play in the differential spider and side gears. How might the technician fix the problem?

Replace the spider and side gear thrust washers

Replace the side gears

Replace the side gears and thrust washers

Replace the spider gears

Correct! Wrong!

If a crown and pinion gear teeth contact pattern is properly adjusted the pattern imprint design left will:

Slightly overrun the toe of the gear

Slightly overrun the heel of the gear

Come close to, but not touch, any edge of the gear tooth

Come to within 1/32 of an inch of the gear toe

Correct! Wrong!

During disassembly, the technician notices slight marks on the face of the thrust block. What would this indicate?

The thrust block must be replaced

The thrust block is doing its job

The thrust block is out of adjustment

The thrust block should be resurfaced

Correct! Wrong!

What should a technician do when repairing a differential equipped with an internal lubrication pump?

Replace all internal hoses or lines

Pack the pump full of lithium-based grease to ensure priming of the system after installation

Replace all external hoses

Inspect the pump operation, and inspect all oil passages

Correct! Wrong!

If the rear end ratio is 5.29:1, the driveshaft is turning at 1400 rpm, what would the wheel RPM be? (rounded to the nearest rpm)

264

2640

740

7406

Correct! Wrong!

On a traditional differential assembly, while cornering, if the inner wheel turns at 7/8 vehicle speed, how fast does the outer wheel turn?

7/8

1

1 1/8

1 1/4

Correct! Wrong!

When crown and pinion gears are used in conjunction with a spur and bull gear set in the same axle assembly, you have:

Single reduction

Double reduction

Triple reduction

Either single or double reduction

Correct! Wrong!

An amboid gear set has:

More than one tooth in contact at one time

A quieter operation than spur gears

The pinion above centre line of the crown or ring gear

All of the above

Correct! Wrong!

To correct a situation where a pinion bearing preload is too loose, you would need to:

Remove shims from under the bearing cage

Install a smaller spacer between the pinion bearings

Install a larger spacer or shim between the pinion bearings

Add shims under the bearing cage

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Show hint

Correct! Wrong!

On a typical off road vehicle or a large bed truck with a planetary gear system mounted in the wheel assembly, which member of the planetary is attached to the AXLE HOUSING?

Sun

Carrier

Ring

Planets

Correct! Wrong!

When a driver controlled traction differential is in the locked position, the differential action is eliminated.

True

False

Correct! Wrong!

Wheel spin out (vehicle stuck and only one wheel turning on an axle) and the resulting heat, which components of a differential is most likely to be damaged first?

Crown gear

Pinion gear

Side gears

Differential thrust washers

Correct! Wrong!

All of the statements below are correct in that damage will occur over time. Which statement below is likely to take the most time to cause damage?

Damage from one wheel spin out will occur much faster on a loaded vehicle than on an unloaded one

Damage from one wheel spin out, will occur much faster on a unloaded vehicle than on an loaded one

Damage from one wheel spin out will occur more rapidly if a driver selects a higher gear and spins the axle faster

Damage from one wheel spin out will occur more rapidly if a driver increases throttle position and spins the axle faster

Correct! Wrong!

A technician finds gears, shafts and bearings that are blue/black in color when disassembling a carrier. The most likely cause of this discoloration is:

Normal wear

Lack of lubrication

Contaminated lubrication

Shock loading

Correct! Wrong!

When rebuilding a carrier assembly it is important to lightly draw file the flat mating surfaces to remove any bumps or burrs. What benefits are achieved by doing this?

Less chance of oil leaks

Truer bearing alignment

Truer gear contact

All of the above

Correct! Wrong!

If one or more rivets are found to be loose between a case half and a crown gear you should replace all the rivets or replace with a bolt set:

True

False

Correct! Wrong!

In the illustrations of gear tooth contact patterns, which pattern indicates that the pinion is in too far?

A

B

C

D

E

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Show hint

Correct! Wrong!

In the illustrations of gear tooth contact patterns, which pattern indicates that the pinion is too far out?

A

B

C

D

E

/wp-content/uploads/2022/02/q40_1.jpg

Show hint

Correct! Wrong!

In the illustrations of gear tooth contact patterns, which pattern indicates that there is too little backlash?

A

B

C

D

E

/wp-content/uploads/2022/02/q41.jpg

Show hint

Correct! Wrong!

In the illustrations of gear tooth contact patterns, which pattern indicates that there is too much backlash?

A

B

C

D

E

/wp-content/uploads/2022/02/q42.jpg

Show hint

Correct! Wrong!

In the illustrations of gear tooth contact patterns, which pattern indicates a correct tooth contact?

A

B

C

D

E

/wp-content/uploads/2022/02/q43_0.jpg

Show hint

Correct! Wrong!

In a full time four wheel drive vehicle, or a tandem drive axle truck what is found in the transfer case or power divider?

differential

high an low range

planetary gear set

slip clutch

Correct! Wrong!

If a differential assembly is noisy only on turns, one of the causes might be:

a loose or worn pinion bearings

worn differential spyder gears

incorrectly mated axle splines

worn crown and pinion gears

Correct! Wrong!

To determine the pinion bearing pre-load:

take the spring-scale reading while the housing first starts to rotate.

take the spring scale reading when the pinion is rotating.

multiply the scale reading times the diameter of the bearing cage.

divide the scale reading by the diameter of the cage.

Correct! Wrong!

Pinion to ring gear depth is increased or decreased by:

different bearing spacer thickness

adding or subtracting shims

moving the threaded adjusters

varying the torque on the yoke nut

Correct! Wrong!

Two speed differentials use shift control devices mounted externally on the case, that use ____________________ to operate gear maneuvering devices internally in the differential, for speed changes.

electric or air control

mechanical cable linkage

vacuum motors

dual shifting magnetic forks

Correct! Wrong!

In a single axle differential unit, the cross is driven by ______________ when the unit is under power.

case halves

spider gears

side gears

axles

Correct! Wrong!

Excessive differential noise only when coasting downhill, could be caused by:

improper lubrication

too much pre-load on the carrier bearings

loose pinion bearings

bent axle shaft

Correct! Wrong!

Before you begin to take a final drive apart you should:

loosen all the fasteners 1/2 turn

wash the entire area thoroughly

Magnaflux the housing

check the sprocket for cracks

Correct! Wrong!

Misalignment of gears will generally cause:

spalling

cracking

interfere wear

abrasive wear

Correct! Wrong!

One advantage to a final drive is:

it reduces the weight of the machine

it allows the other power train components to carry less load

it has bigger gears than any other type of drive

it does not require lubrication

Correct! Wrong!

The type of reduction which may be inboard or outboard is the:

planetary drive

electrical drive

double reduction drive

single reduction drive

Correct! Wrong!

Inboard planetary drives are easily serviced without requiring sprocket removal.

true

false

Correct! Wrong!

What drives the pinion gear on a hydrostatic type final drive?

Steering clutch shaft

Bevel gear shaft

Hydraulic motor

All of the above

Correct! Wrong!

An advantage of double reduction final drives over single reduction final drives is:

Increase speed and decrease torque

Decrease speed and increase torque

Increase speed and increase torque

Decrease speed and decrease torque

Correct! Wrong!

Excessive wear on crawler final drive bearings could be caused by:

Track too tight

Track too loose

Badly worn sprocket

Excessive side hill work

Correct! Wrong!

In an inboard planetary final drive, the ring gear is the:

Held member

Drive member

Driven member

Neutral member

Correct! Wrong!

In a planetary final drive, the sun gear is the:

Held member

Drive member

Driven member

Neutral member

Correct! Wrong!

The main drawback of a single universal joint is that:

Universal joints are "phased" to:

Some slip joints are coated with a nylon compound to:

The two most significant factors in reducing drive line failure is:

To check a driveline assemble for run-out, you must perform dial indicator tests at three different locations on:

The prime function of a drive line is to:

One of the first signs of drive line trouble is usually:

A constant velocity joint eliminates the:

On a single shaft with parallel driveline alignment if the transmission is at +3 deg. the front differential should be at:

A differential drive axle which does NOT support load and only supplies torque to drive the wheel is called:

A differential drive axle which does support load and supplies torque to drive the wheel is called:

Power transmission through the differential until when the vehicle travels straight ahead is, from the pinion through the ring gear and from the casehalf to the:

To ensure proper lubrication of the interaxle differential, some large carriers assemblies use:

The simplest type of wheel traction equalization is the:

If the operators were to pay attention, one of the first symptoms noticed of pending carrier trouble would be:

Gear tooth fracture is frequently caused by:

Numbers etched on the pinion gear indicate: 1. set number. 2. tolerance of the gear set and 3. ___________________________.

Excessive toe adjustment on the drive side the pinion gear to the driven side of the ring gear will require _________________________.

A differential shows spalling on the teeth of the crown gear, while the gear teeth of the pinion have no signs of wear. What should the technician do?

A technician is measuring pinion to crown backlash with a dial indicator. After following the proper procedure, the dial indicator reads "0" backlash. What should the technician do next?

If the backlash measurement for the ring gear is out of specifications, how can the backlash measurement be brought into tolerance?

A technician notices excessive play in the differential spider and side gears. How might the technician fix the problem?

If a crown and pinion gear teeth contact pattern is properly adjusted the pattern imprint design left will:

During disassembly, the technician notices slight marks on the face of the thrust block. What would this indicate?

What should a technician do when repairing a differential equipped with an internal lubrication pump?

If the rear end ratio is 5.29:1, the driveshaft is turning at 1400 rpm, what would the wheel RPM be? (rounded to the nearest rpm)

On a traditional differential assembly, while cornering, if the inner wheel turns at 7/8 vehicle speed, how fast does the outer wheel turn?

When crown and pinion gears are used in conjunction with a spur and bull gear set in the same axle assembly, you have:

An amboid gear set has:

To correct a situation where a pinion bearing preload is too loose, you would need to:

On a typical off road vehicle or a large bed truck with a planetary gear system mounted in the wheel assembly, which member of the planetary is attached to the AXLE HOUSING?

When a driver controlled traction differential is in the locked position, the differential action is eliminated.

Wheel spin out (vehicle stuck and only one wheel turning on an axle) and the resulting heat, which components of a differential is most likely to be damaged first?

All of the statements below are correct in that damage will occur over time. Which statement below is likely to take the most time to cause damage?

A technician finds gears, shafts and bearings that are blue/black in color when disassembling a carrier. The most likely cause of this discoloration is:

When rebuilding a carrier assembly it is important to lightly draw file the flat mating surfaces to remove any bumps or burrs. What benefits are achieved by doing this?

If one or more rivets are found to be loose between a case half and a crown gear you should replace all the rivets or replace with a bolt set:

In the illustrations of gear tooth contact patterns, which pattern indicates that the pinion is in too far?

In the illustrations of gear tooth contact patterns, which pattern indicates that the pinion is too far out?

In the illustrations of gear tooth contact patterns, which pattern indicates that there is too little backlash?

In the illustrations of gear tooth contact patterns, which pattern indicates that there is too much backlash?

In the illustrations of gear tooth contact patterns, which pattern indicates a correct tooth contact?

In a full time four wheel drive vehicle, or a tandem drive axle truck what is found in the transfer case or power divider?

If a differential assembly is noisy only on turns, one of the causes might be:

To determine the pinion bearing pre-load:

Pinion to ring gear depth is increased or decreased by:

Two speed differentials use shift control devices mounted externally on the case, that use ____________________ to operate gear maneuvering devices internally in the differential, for speed changes.

In a single axle differential unit, the cross is driven by ______________ when the unit is under power.

Excessive differential noise only when coasting downhill, could be caused by:

Before you begin to take a final drive apart you should:

Misalignment of gears will generally cause:

One advantage to a final drive is:

The type of reduction which may be inboard or outboard is the:

Inboard planetary drives are easily serviced without requiring sprocket removal.

What drives the pinion gear on a hydrostatic type final drive?

An advantage of double reduction final drives over single reduction final drives is:

Excessive wear on crawler final drive bearings could be caused by:

In an inboard planetary final drive, the ring gear is the:

In a planetary final drive, the sun gear is the:

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Heavy-Duty Mechanic - Trucks & Equipment