Final Drives

The type of gear reduction system which may be classified 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!

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?

A is right

B is right

Both are right

Neither is right

Correct! Wrong!

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

True

False

Correct! Wrong!

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

True

False

Correct! Wrong!

One advantage to a planetary 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!

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 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!

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

True

False

Correct! Wrong!

In a planetary final drive:

The ring gear is usually attached to the wheel

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?

A is right

B is right

Both are right

Neither 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!

In a planetary gear set if the ring is held, the carrier is the drive and the sun is driven the result is:

Forward reduction

Forward overdrive

Reverse reduction

Reverse overdrive

Correct! Wrong!

Final Drives

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

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

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

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

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

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?

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

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

One advantage to a planetary final drive is:

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

Final drive seal leakage may be caused by:

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

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

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.

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

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

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

In a planetary final drive:

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?

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

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

In a planetary gear set if the ring is held, the carrier is the drive and the sun is driven the result is:

Success!

Heavy-Duty Mechanic - Trucks & Equipment