Differentials and Final Drives Quiz

If rear end ratio is 5.29:1 the driveshaft is turning 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!

In a differential, the cross is driven by __ when the unit is under power.

case halves

spider gears

side gears

axles

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!

A drive axle assembly that has full floating axles:

uses the axle to hold the wheel hubs on the vehicle.

would have retainers at the diff end of the axle.

would not loose a wheel due to a broken axle.

all of the above.

Correct! Wrong!

If pinion bearing preload is too loose:

remove shims from under the bearing cage.

install a smaller spacer between the pinion bearings.

install a larger spacer between the pinion bearings.

add shims under the bearing cage.

Correct! Wrong!

The purpose of the thrust block or bolt in a rear end unit is to control:

pinion deflection.

differential end play.

crown gear end play.

crown gear deflection.

Correct! Wrong!

If one wheel of a tandem rear axle is raised off the floor and is driven by the engine, what is the speed of the wheel compared to the vehicle speedometer reading?

It is the same

2 times

3 times

4 times

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 wheel hub?

Sun

Carrier

Ring

Planets

Correct! Wrong!

Gears with the teeth cut at an angle to the axis of the gear are ___________gears.

Helical

Spur

Ring

Sun

Correct! Wrong!

In a tandem axle power divider, what is the correct power flow when unlocked?

Input shaft, crown gear, case half, cross, spider gears, side gears, axles.

Input shaft, through shaft, crown, pinion, axles.

Input shaft, cross, spider gears, side gears, to through shaft and helical gear.

Input shaft, hellical gear, spider gears, cross, side gears.

Correct! Wrong!

When adjusting the thrust bolt on a rebuilt carrier the procedure is to turn the screw in until it contacts the crown gear and:

tighten the jam nut.

back out the screw 1 turn and tighten the jam nut.

back out the screw 1/2 turn and tighten the jam nut.

back out the screw 1 1/2 turns and tighten the jam nut.

Correct! Wrong!

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

True

False

Correct! Wrong!

Spin out (vehicle stuck and only one wheel turning on an axle) is likely to cause initial damage to which component(s) of a rear end?

Crown Gear

Pinion Gear

Side Gears

Thrust Washers

Correct! Wrong!

Technician A says that damage from spin out will occur much faster on a loaded vehicle than on an unloaded one. Technician B says that damage from spin out will occur more rapidly if a driver selects a higher gear and spins the axle faster. Who is correct?

Technician A

Technician B

Both A and B

Neither A or B

Correct! Wrong!

With the power divider in the locked position it is possible to have two wheels spinning on the rear differential and one wheel spinning on the front differential?

True

False

Correct! Wrong!

Which type of force is normally used to shift the inter-axle differential into lock?

Hydraulic

Air Pressure

Centrifugal

Manual

Correct! Wrong!

Technician A says that the lubricant in a rear end SHOULD be changed on a regular basis as the oil becomes contaminated with small metal particles as normal wear occurs. Technician B says that an extreme pressure lubricant should NOT be used as it will gum up the thrust washers. Who is correct?

Technician A

Technician B

Both A and B

Neither A or B

Correct! Wrong!

Technician A says that if you find a damaged pinion gear and the crown gear is in good shape you should change only the damaged pinion gear and reuse the crown gear. Technician B says that prior to disassembling a carrier for rebearing you should measure the backlash and that if it is within spec''s and the crown and pinion are to be reused you should use this same backlash when reassembling. Who is correct?

Technician A

Technician B

Both A and B

Nither A or B

Correct! Wrong!

A technician find 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.

drive abuse.

Correct! Wrong!

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

Less chance of oil leaks

Tuer bearing alignment

Tuer gear contact

All of the above

Correct! Wrong!

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

True

False

Correct! Wrong!

On a full-floating axle, what supports the vehicle''s weight?

The axle housing

The axle shaft

The wheel assembly

The inner axle bearing

Correct! Wrong!

A full-floating wheel assembly is being inspected. Technician A says that on disc wheels, the wheel and hub are combined into a single unit. Technician B says a wheel bearing may be locked in place by either an adjusting and lock nut assembly, split forged nut, or castellated nut and cotter pin assembly. Who is right?

Technician A

Technician B

Both A and B.

Neither A or B.

Correct! Wrong!

The following are all reasons to replace the ring and pinion EXCEPT:

burnishing and/or hobbing on most of the gear teeth faces.

scoring of the gear teeth faces

light cracking of the gear teeth faces.

minor spalling of the gear teeth faces.

Correct! Wrong!

When rebuilding a differential that has 200,000 miles of service on it, a technician notices faint, equally spaced grooves on the bearing caps. Technician A says the bearing caps are showing signs of a spun bearing and must be replaced. Technician B says the marks are from the original machining process and do not need to be replaced. Who is right?

Technician A

Technician B

Both A and B

Neither A or B

Correct! Wrong!

The following are all checks that should be made to full floating axle shafts to determine whether or not replacement is necessary EXCEPT:

bending of the axle shaft.

twisting of the axle shaft.

slightly scored or pitted bearing race surfaces.

pitting or chipping of the axle shaft splines.

Correct! Wrong!

The component which allows axles to turn at different speeds is the:

Hypoid

Pinion

Double Reduction

Differential

Correct! Wrong!

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

differential housing to the axles.

pinion gear to the axles.

bearing housing to the spider.

differential case and side gears to the axles.

Correct! Wrong!

A technician is measuring differential bearing preload. After following the proper procedure, the dial indicator reads "0". What should the technician do next?

Loosen the adjusting ring one notch.

Continue with assembly; the preload is set correctly.

Tighten each bearing adjusting ring one notch.

Adjust the bearing preload of the other side of the differential.

Correct! Wrong!

A truck with a tandem axle has a rotational noise coming from the rear. What is the most accurate way to determine if the noise is from the wheel bearings or from the differential?

Jack the axle up and hand turn the differential while feeling for a binding or stiff condition.

Remove the differential carrier and visually inspect.

Disconnect the propeller shaft, then raise the axle, and listen for the same noise while turning the wheel.

Drain the axle housing and refill with a lightweight gear oil. Then drive the truck and listen for a change of pitch in the original noise.

Correct! Wrong!

A technician has an overheating problem with both axles of a tandem drive axle configuration. All of the following could be causes EXCEPT:

poor quality axle fluid.

wheel bearings.

the inter axle differential not operating smoothly.

continuous vehicle overloading.

Correct! Wrong!

Technician A says drive pinion depth should only be set after you properly pre load the pinion bearing cage. Technician B says that setting the drive pinion depth requires adjustment of the ring gear. Who is right?

Technician A

Technician B

Both A and B

Neither A or B

Correct! Wrong!

A dial gauge indicates the run out measurement for the ring gear is out of specifications, and a recheck of correct assembly and torques was done. How might the runout measurement be brought back into tolerance?

Reset the pre load of the differential side bearings.

Remove the ring gear and reinstall with a 90 degree rotation on 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!

Differential noise which occurs only during turns indicates a problem with:

The Pinion Bearings

The Differential

The Carrier Bearings

The Input Shaft Bearings

Correct! Wrong!

The space between two gear pitch lines is called:

Backlash

Center

Clearance

Preload

Correct! Wrong!

Numbers etched on the pinion gear indicate set number, tolerance of the gear set and:

model number and year of equipment.

preload on the bearings.

clearance between gears.

pinion depth.

Correct! Wrong!

Too much toe on the drive and coast sides of the gears will require:

A decrease in backlash

An increase in backlash

An increase in pinion depth

A decrease in pinion depth

Correct! Wrong!

The type of gear set that has straight teeth on both the ring gear and the drive pinion is the:

Bevel gear set

Spiral bevel gear set

Hyphoid bevel gear set

Amboid bevel gear set

Correct! Wrong!

A differential shows spalling on the teeth of the ring 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!

A technician notices excessive vertical play in the differential side pinion gears. How should the technician fix the problem?

Split the differential case and replace the side gear pinion thrust washers.

Split the differential case and replace the side pinion gears.

Split the differential case, replace the side pinion gears and thrust washers.

Loosen the differential side pinion gear retaining caps and install new thrust washers.

Correct! Wrong!

During a road test, you notice a noise coming from the axles only during turns. Technician A says that the problem is excessive backlash between the side gears and the spider gears. Technician B says that excessive backlash between the ring and pinion can be the cause. Who is correct?

Technician A

Technician B

Both Technician A and B

Neither Technician A or B

Correct! Wrong!

An inter-axle differential in the normal running position will:

drive only the front axle.

divide torque equally between the axles.

drive only the rear axle.

have differential action.

Correct! Wrong!

Pinion 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!

To determine the pinion bearing pre load:

take the spring scale reading while the housing is rotating.

take the spring scale reading when the housing first starts to rotate.

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

divide the scale reading by the diameter of the cage.

Correct! Wrong!

A high pitched whine in a differential while under acceleration could be caused by:

Incorrect tooth contact

Too much pinion bearing pre load

Faulty spigot bearing

Too much crown/pinion backlash

Correct! Wrong!

An axle which supports load and drives the wheel is called:

A full floating axle

A split axle

A semi-floating axle

A live axle

Correct! Wrong!

An axle which supports weight but does not provide drive is called:

A full floating axle

A dead axle

A live axle

A semi-floating axle

Correct! Wrong!

If traction is lost to one wheel in a standard single reduction differential:

All torque will be transmitted to the wheel with no traction

All torque will be transmitted to the wheel with all the traction

No torque will be transmitted at all

Torque will be transmitted equally to both wheels

Correct! Wrong!

A truck has an extremely hot wheel hub after a test drive. The LEAST likely cause would be:

Axle shaft damage

Wheel hub bearing damage

Air line damage to the brakes

Poor quality lubricant

Correct! Wrong!

When installing a new differential carrier into an existing axle housing, a technician should check:

For differential carrier mounting flange squareness

The axle housing mating flange for nicks, scratches, or burrs

the differential carrier mating flange For nicks, scratches, or burrs

Both mating surfaces for a good, clean, and tight fit

Correct! Wrong!

How would a technician replace a ring gear once the rivets are removed?

Press out the old one, heat the new ring gear in water, and assemble

Simply allow the old ring gear to separate from the differential case, and install the new one

Pry the old ring gear off the differential, and install the replacement ring gear with a press

Lightly hammer the old ring gear off the differential case, and use a torch to heat the differential case before installing the new ring gear.

Correct! Wrong!

A proper gear tooth contact pattern 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!

What should a technician do when servicing the gears of a differential equipped with a 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

Check the pump for smooth operation, and blow forced air through all passages

Correct! Wrong!

When measuring and setting pinion bearing pre load:

Note the shim size used and use the same size during installation

Note the shim size used and choose one that is 0.001 inch (0.025 mm) smaller for installation

Note the shim size used and choose one that is 0.001 inch (0.025 mm) larger for installation

Never use the same shim to test pre load and install in the axle

Correct! Wrong!

The primary function of a double reduction carrier is to:

Decrease gear load

Eliminate heat build-up due to torque

Allow the machine to do additional work

Increase torque to the drive axles

Correct! Wrong!

To ensure proper lubrication of the inter axle differential, some carriers use a:

Special splash device on the ring gear

Input shaft spline driven pumps

Lower bearing mountings

Higher fluid levels than normal differentials

Correct! Wrong!

Excessive differential noise only when coasting could be caused by:

Improper lubrication

Too much pre load on the carrier bearings

Loose or scored pinion bearings

Bent axle shaft

Correct! Wrong!

You are removing a ring gear from the differential case. Technician A uses a hammer and chisel to remove the old rivets. Technician B uses a drill and punch to remove the old rivets. Who is right?

Technician A

Technician B

Both A and B

Neither A or B.

Correct! Wrong!

You are setting the correct thrust screw tension on a differential that has a thrust block. Technician A says you turn the thrust screw until it stops against the ring gear or thrust block, then tighten one-quarter turn, and lock the jam nut. Technician B says 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?

Technician A

Technician B

Both A and B

Neither A or B

Correct! Wrong!

A common cause of damage to an inter axle differential is:

Failure to shift properly

Air leaks

Universal joint wear

Mismatched tires

Correct! Wrong!

Shock loads can often be the cause in gear tooth fracture. A contributing factor may be:

Poor lubrication

Excessive tooth contact

Pitted gear teeth

Overheating

Correct! Wrong!

A vehicle with a lot of drive line vibration could have:

Uneven working angles

No working angles

Parallel working angles

Even working angles

Correct! Wrong!

The simplest type of traction equalizer is the:

Power divider

Proportional differential

Differential lock

Multi-clutch equalizer

Correct! Wrong!

The two methods of drive line alignment are the parallel method and:

Intersecting line method

Vertical line method

Constant velocity method

Horizontal method

Correct! Wrong!

Before beginning any repair to a drive system always:

Allow it to cool sufficiently

Drain all fluids as required

Lock out or tag out the equipment

Read the operators request for service

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!

The main drawback of using a single cross universal joint applied to a driveshaft system is that:

The universal joint changes torque requirements

The universal joint requires constant lubrication

The drive shaft sections are too long

The universal joint does not transfer uniform rotating speed

Correct! Wrong!

Universal joints and drive shaft yokes are "phased" to:

Reduce the twisting action

Eliminate torsional vibrations

Simplify assembly of the sections to each other

Allow the shaft to change length when the suspension moves up and down

Correct! Wrong!

Propeller shafts must be as short as possible and as large in diameter as possible to:

Transmit torque without bending or vibrating

Eliminate oscillation

Increase support through bearing units

Make disassembly easier

Correct! Wrong!

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

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 two joint assembly for alignment, you must perform dial indicator tests at three different locations on:

The transmission output flange

The carrier flange

The wheel hubs

The propeller shaft

Correct! Wrong!

What should a technician do when replacing a support bearing assembly?

Lubricate the bearing

Apply lubricant to the outer bearing race to help press the bearing into place

Coat the bearing seal surfaces with grease

Pay close attention to proper orientation of the support bearing assembly

Correct! Wrong!

A transfer case with an air actuator will not shift from the low gear ratio up to 1:1. The most likely first check is:'

A broken shifter shaft spring

A faulty air compressor

Supply air line pressure

A broken shifter shaft

Correct! Wrong!

A technician finds dirt contamination when removing the 4X4 axle end-locking hub. What should the technician do?

Replace the entire hub

Replace the bearings and repack the hub

Repack the bearings

Inspect and repack the bearings and replace the seal

Correct! Wrong!

The recommended maximum run out on a driveshaft measured at the shaft centre is:

.005

.010

.015

.020

Correct! Wrong!

It is necessary to take the slip yoke with you to a machine shop when you are taking a drive shaft in to be re-tubed.

True

False

Correct! Wrong!

For good cancellation, working angles should be no more than __________ deg. difference on a drive shaft.

1

3

5

7

Correct! Wrong!

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

Loss of power

Vibration

Difficult shifting

Poor clutch engagement

Correct! Wrong!

If a slip yoke is seized up on an inter axle driveshaft damage to the___________________________ may occur.

Output shaft bearings on rear of front differential

U-joints

Pinion bearings of rear differential

All of the above

Correct! Wrong!

Companion flanges are commonly used on the driveshaft where space is a factor.

True

False

Correct! Wrong!

A truck driver complains that his tractor will not shift out of inter axle differential lock. Which of these could be the cause?

Shift shaft spring

A broken shift shaft

An open or damaged air line

A striped differential clutch collar

Correct! Wrong!

A driver reports a relatively sudden onset of drive line noise. After a visual examination of the undercarriage, one of the first things to check when a would be?

Drive line angles

A seized u-joint or slip joint

Rear axle alignment

Bent frame

Correct! Wrong!

Which of the following will not affect the drive shaft balance?

Missing balance weights

U-joint lubrication

Foreign material stuck to shaft

Bends

Correct! Wrong!

U-joints should be lubricated more frequently in excessive road spray conditions.

True

False

Correct! Wrong!

What is a good way to separate transmission noise from drive axle or wheel bearing noise?

Test the vehicle on downhill grades to eliminate torque on the transmission

Place the drive axle on jackstands, and use the transmission to spin the wheels with no load on them

Lightly apply the brakes while travelling down the road, and listen for any change in the noise

Go for a test drive with the driver of the truck

Correct! Wrong!

A driveshaft without a slip yoke is usually found:

Between the main transmission and the auxiliary transmission

Between the main transmission and the steady bearing

Between the steady bearing and the front differential

Between the front differential and the rear differential

Correct! Wrong!

With parallel drive line alignment if the transmission is at -3 deg. the front differential should be at:

+3 deg.

-3 deg.

+6 deg.

-6 deg.

Correct! Wrong!

Before sliding a slip yoke off a stub shaft you should:

Grease the slip yoke

Check the drive shaft for balance

Remove the expansion plug

Put alignment marks on the slip yoke and stub shaft

Correct! Wrong!

Vibration of a drive shaft could be caused by:

Shaft yokes out of phase

Wrong drive angle

Undercoating on shaft

Any of the above

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!

Phasing of a drive shaft refers to:

Yoke alignment

Working angles

Grease fitting alignment

Knuckling action

Correct! Wrong!

During a routine drive axle oil change, a technician notices a few metal particles on the magnetic plug of the drive axle. What should the technician do first?

Inform the customer that further investigation is needed

Inform the customer of the condition, and tell them to monitor the amount of particles

Do not follow up with the customer, since some metal particles are normal

Begin to disassemble the drive axle to find the cause

Correct! Wrong!

The purpose of a slip yoke and stub shaft (tube shaft) in a drive line is to:

Reduce vibration

Reduce knuckling

Allow for changes in length of shaft

All of the above

Correct! Wrong!

A driver complains of PTO vibration only when the vehicle is shifting gears at low speed. The vibration is likely caused by:

Broken gear teeth inside the PTO

A stiff or frozen U-joint in the PTO shaft

Something else; the driver is mistaken to think the noise and/or the vibration is from the PTO

Bent or out of balance PTO drive shaft

Correct! Wrong!

When greasing a U-joint one should:

Not force grease past seals

Ensure grease exits from all 4 cups

Grease opposite cups separately

Only use low-temp grease

Correct! Wrong!

Universal joints are used in drive lines to:

Permit longer drive line components

Make disassembly of the drive line easier

Connect two components on different planes

Limit side play in components

Correct! Wrong!

A technician notices a small amount of whitish milky substance when changing the fluid in an axle. This evidence of water is likely caused by:

Common condensation

Infrequent driving and short trips

The axle being submerged in water

The vehicle being frequently driven during rainy or wet conditions

Correct! Wrong!

A drive axle housing mating surface is nicked up. Technician A says a proper repair job requires you to use a torch to fill the gouges and then file them smooth. Technician B says a proper job requires you to grind and sand smooth any imperfections. Who is right?

Technician A

Technician B

Both A and B

Neither A or B.

Correct! Wrong!

When replacing drive shaft center support bearings, a technician should always:

Look for any shims during removal of the old bearing

Pack the bearing full of grease

Measure drive line angles once the new component is installed

Use hand tools; air tools could twist the mounting cage and shorten bearing life.

Correct! Wrong!

Technician A says that every time you remove a hub from an oil lubricated type axle bearing, you should repack the bearing with grease. Technician B says that every time you remove a hub from a grease-lubricated type axle bearing, you should repack the bearing with grease. Who is right?

Technician A

Technician B

Both A and B

Neither A or B

Correct! Wrong!

If, when lubricating a U-joint, fresh lube can be seen at all bearing seals, this means:

The trunions are worn and need to be replaced

The bearings are worn and need to be replaced

The seals are worn and need to be replaced

The U-joint has been properly lubed

Correct! Wrong!

What should a technician check for when replacing U-joints?

Driveshaft balance

Yoke misalignment

Yoke phasing

Dirt or other clutter on the driveshaft

Correct! Wrong!

Technician A says that transmission mounts are used to absorb torque from the engine. Technician B says that transmission mounts will absorb drive train vibration. Who is right?

Technician A

Technician B

Both A and B

Neither A nor B

Correct! Wrong!

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

Differential

High and low range

Planetary gear set

Slip clutch

Correct! Wrong!

A driveshaft should be able to:

Rotate at high speed

Transmit maximum low gear torque

Operate under changing angles

All of the above

Correct! Wrong!

Hard surfacing flaked off (spalling) of four trunnions on a cross with NO sign of brinelling would indicate:

Normal life wear

A drive shaft with no working angle

Excessive Jake brake operation

Rough shifting

Correct! Wrong!

Brinelling of a U-joint is usually caused by:

A sharp working angle

Little or no working angle

Normal working angle

Constantly changing working angle

Correct! Wrong!

A non-constant velocity driveshaft with a working angle speeds up and shows down twice per revolution.

True

False

Correct! Wrong!

On an inter axle drive line (drive line between differentials on a tandem axle vehicle), the angle of the yoke on the rear of the front differential is +4 deg., the interaxle driveshaft is +7 deg., the yoke on the rear differential is +10 deg. Is this satisfactory?

Yes

No

Correct! Wrong!

Ideally the minimum U-joint working angle on heavy duty truck applications should be no less than:

1 deg

3 deg.

5 deg.

7 deg.

Correct! Wrong!

Steady bearing are adjustable to correct drive line angles.

True

False

Correct! Wrong!

The type of gear reduction system which may be classed as either inboard or outboard, is the:

Planetary drive

Electrical drive

Double reduction drive

Single reduction drive

Correct! Wrong!

Planetary final drives used on modern heavy equipment and trucks are typically _______________.

Single reduction

Double reduction

Triple reduction

Non reduction

Correct! Wrong!

Typically, single reduction final drives use a splash system of lubrication.

True

False

Correct! Wrong!

The planetary double reduction carrier has:

A movable sun gear

A stationary sun gear

Two sun gear

Two pinions

Correct! Wrong!

Before you begin to remove a final drive assembly off of a piece of equipment, you should:

Loosen all the fasteners 1/2 turn

Clean the entire area thoroughly

Magnaflux the housing

Check the sprocket for cracks

Correct! Wrong!

Misalignment of gears in any type of drive system will generally cause:

Spalling

Cracking

Interference wear

Abrasive wear

Correct! Wrong!

Mechanic A says that the manufacturers recommendation is that bent axles can often be straightened and reused. Mechanic B says that, if equipped, the oil pump, filter and galleries should be serviced thoroughly when the differential or final drive is repaired. Who is right?

Technician A

Technician B

Both A and B are right

Neither A or B is right

Correct! Wrong!

All gears and bearings should be installed dry. They will receive adequate lubrication when you fill the housing.

True

False

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!

One function of the dead axle is:

To carry the drive pinion

To support the track frame

To turn the sprocket

To drive the transmission

Correct! Wrong!

The simplest type of shovel drive is:

Chain

Hydraulic

Direct mechanical

Electric

Correct! Wrong!

Inboard planetary drives are easily serviced without requiring drive sprocket removal.

True

False

Correct! Wrong!

What drives the sun 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 a planetary final drive, the ring gear is the:

Held member

Drive member

Driven member

Neutral member

Correct! Wrong!

Final drive seal leakage may be caused by:

Faulty final drive bearings

Mismatched seal rings

Damage to seal bore

All of the above

Correct! Wrong!

Why is it necessary to change oil in a final drive assembly?

Remove condensation build-up in the oil

Remove excessive metal particles

Remove acid build-up in the oil

All of the above

Correct! Wrong!

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

Held member

Drive member

Driven member

Neutral member

Correct! Wrong!

Proper final drive servicing, at the correct intervals is not necessary to prevent excessive wear and damage as long as the operator uses the machine correctly.

True

False

Correct! Wrong!

Before you begin any final drive work, you should always:

Pre-lube any replacement parts

Block the machine so that it will not move

Drain the final drive while the oil is still hot

Loosen the wheel nuts

Correct! Wrong!

Seals in final drives must only be replaced if they are damaged or do not look like they will perform up to standards.

True

False

Correct! Wrong!

Mechanic A says that an accumulation of metal chips in the lubricant from a final drive is normal and can be ignored during service. Mechanic B says that chain tension on grader final drives is automatically adjusted and does not require inspection unless the drive fails. Who is right?

Technician A

Technician B

Both A and B are right

Neither A or B are right

Correct! Wrong!

Single reduction spur gears are lubricated by a pressure pump driven from the engine.

True

False

Correct! Wrong!

In a planetary final drive:

The sun gear is attached to the stationary axle housing

The planet carriers are attached to the moving axle

The planet carriers are attached to the wheel

Correct! Wrong!

Mechanic A says that outboard planetaries are most common because they are the most convenient to service. Mechanic B says that in order to service an outboard planetary you must first jack up the machine and remove the tires. Who is right?

Technician A

Technician B

Both A and B are right

Neither A or B is right

Correct! Wrong!

Planetary gears have an advantage over other types of gears in that:

The load is spread over more gears and they are more compact

The chain does not have to be as long as in other drives

They do not require extensive lubrication

They provide only one range of gear reduction

Correct! Wrong!

In a chain drive system attached to a final drive, a change in driven speed of the wheels can be accomplished by:

Changing the length of the chain

Shifting the final drive

A difference in size of the chain sprockets

The size of the spur gear

Correct! Wrong!

A final drive axle that is called a "live" axle:

Supports none of the machine weight

Provides drive only

Does not provide any of the drive

Supports weight and provides drive

Correct! Wrong!

A final drive is required to:

Provide a means of changing direction

Reduce transmission output load and increase torque

Allow for changes in load and suspension requirements

Serve as a reservoir for the wheel bearings

Correct! Wrong!

Technician A says that a planetary gear set in a double reduction drive axle can be diagnosed using the same steps as those used on a planetary two-speed axle. Technician B says that the second gear reduction comes from two helically cut gears. Who is right?

Technician A

Technician B

Both A and B

Neither A or B

Correct! Wrong!

If rear end ratio is 5.29:1 the driveshaft is turning 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?

In a differential, the cross is driven by __________ ____________ when the unit is under power.

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:

A drive axle assembly that has full floating axles:

If pinion bearing preload is too loose:

The purpose of the thrust block or bolt in a rear end unit is to control:

If one wheel of a tandem rear axle is raised off the floor and is driven by the engine, what is the speed of the wheel compared to the vehicle speedometer reading?

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 wheel hub?

Gears with the teeth cut at an angle to the axis of the gear are ___________gears.

In a tandem axle power divider, what is the correct power flow when unlocked?

When adjusting the thrust bolt on a rebuilt carrier the procedure is to turn the screw in until it contacts the crown gear and:

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

Spin out (vehicle stuck and only one wheel turning on an axle) is likely to cause initial damage to which component(s) of a rear end?

Technician A says that damage from spin out will occur much faster on a loaded vehicle than on an unloaded one. Technician B says that damage from spin out will occur more rapidly if a driver selects a higher gear and spins the axle faster. Who is correct?

With the power divider in the locked position it is possible to have two wheels spinning on the rear differential and one wheel spinning on the front differential?

Which type of force is normally used to shift the inter-axle differential into lock?

Technician A says that the lubricant in a rear end SHOULD be changed on a regular basis as the oil becomes contaminated with small metal particles as normal wear occurs. Technician B says that an extreme pressure lubricant should NOT be used as it will gum up the thrust washers. Who is correct?

A technician find 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 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 crown gear you should replace all the rivets or install a complete bolt set.

On a full-floating axle, what supports the vehicle''s weight?

The following are all reasons to replace the ring and pinion EXCEPT:

The following are all checks that should be made to full floating axle shafts to determine whether or not replacement is necessary EXCEPT:

The component which allows axles to turn at different speeds is the:

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

A technician is measuring differential bearing preload. After following the proper procedure, the dial indicator reads "0". What should the technician do next?

A truck with a tandem axle has a rotational noise coming from the rear. What is the most accurate way to determine if the noise is from the wheel bearings or from the differential?

A technician has an overheating problem with both axles of a tandem drive axle configuration. All of the following could be causes EXCEPT:

Technician A says drive pinion depth should only be set after you properly pre load the pinion bearing cage. Technician B says that setting the drive pinion depth requires adjustment of the ring gear. Who is right?

A dial gauge indicates the run out measurement for the ring gear is out of specifications, and a recheck of correct assembly and torques was done. How might the runout measurement be brought back into tolerance?

Differential noise which occurs only during turns indicates a problem with:

The space between two gear pitch lines is called:

Numbers etched on the pinion gear indicate set number, tolerance of the gear set and:

Too much toe on the drive and coast sides of the gears will require:

The type of gear set that has straight teeth on both the ring gear and the drive pinion is the:

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

A technician notices excessive vertical play in the differential side pinion gears. How should the technician fix the problem?

During a road test, you notice a noise coming from the axles only during turns. Technician A says that the problem is excessive backlash between the side gears and the spider gears. Technician B says that excessive backlash between the ring and pinion can be the cause. Who is correct?

An inter-axle differential in the normal running position will:

Pinion depth is increased or decreased by:

To determine the pinion bearing pre load:

A high pitched whine in a differential while under acceleration could be caused by:

An axle which supports load and drives the wheel is called:

An axle which supports weight but does not provide drive is called:

If traction is lost to one wheel in a standard single reduction differential:

A truck has an extremely hot wheel hub after a test drive. The LEAST likely cause would be:

When installing a new differential carrier into an existing axle housing, a technician should check:

How would a technician replace a ring gear once the rivets are removed?

A proper gear tooth contact pattern will:

What should a technician do when servicing the gears of a differential equipped with a lubrication pump?

When measuring and setting pinion bearing pre load:

The primary function of a double reduction carrier is to:

To ensure proper lubrication of the inter axle differential, some carriers use a:

Excessive differential noise only when coasting could be caused by:

You are removing a ring gear from the differential case. Technician A uses a hammer and chisel to remove the old rivets. Technician B uses a drill and punch to remove the old rivets. Who is right?

A common cause of damage to an inter axle differential is:

Shock loads can often be the cause in gear tooth fracture. A contributing factor may be:

A vehicle with a lot of drive line vibration could have:

The simplest type of traction equalizer is the:

The two methods of drive line alignment are the parallel method and:

Before beginning any repair to a drive system always:

The prime function of a drive line is to:

The main drawback of using a single cross universal joint applied to a driveshaft system is that:

Universal joints and drive shaft yokes are "phased" to:

Propeller shafts must be as short as possible and as large in diameter as possible to:

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

To check a two joint assembly for alignment, you must perform dial indicator tests at three different locations on:

What should a technician do when replacing a support bearing assembly?

A transfer case with an air actuator will not shift from the low gear ratio up to 1:1. The most likely first check is:'

A technician finds dirt contamination when removing the 4X4 axle end-locking hub. What should the technician do?

The recommended maximum run out on a driveshaft measured at the shaft centre is:

It is necessary to take the slip yoke with you to a machine shop when you are taking a drive shaft in to be re-tubed.

For good cancellation, working angles should be no more than __________ deg. difference on a drive shaft.

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

If a slip yoke is seized up on an inter axle driveshaft damage to the___________________________ may occur.

Companion flanges are commonly used on the driveshaft where space is a factor.

A truck driver complains that his tractor will not shift out of inter axle differential lock. Which of these could be the cause?

A driver reports a relatively sudden onset of drive line noise. After a visual examination of the undercarriage, one of the first things to check when a would be?

In a differential, the cross is driven by __ when the unit is under power.