401Db: Transmission Fundamentals

Question 1

The auxiliary section of a transmission can havve which of the following arrangements?

a) two-speed
b) three-speed
c) four-speed
d) all of the above

Answer 1

d) all of the above

401Db

Question 2

What type of gearing can the auxiliary section have?

Answer 2

Range & Splitter
or
Range & Deep Reduction

401Db

Question 3

Where in an auxillary transmission is a synchronizer typically found?

Answer 3

Range Shift
On the mainshaft between the low and high range gears

401Db

Question 4

How is the auxillary transmission output shaft held in position?

Answer 4

By two tapered roller bearings in the rear bearing housing

401Db

Question 5

What gearing combination is provided by a two-speed auxiliary section?

Answer 5

Deep Reduction
Direct

Question 6

What gearing combination is provided by a three-speed auxiliary section?

Answer 6

Deep Reduction
Low Range
High Range

Question 7

What gearing combination is provided by a four-speed auxiliary section?

Answer 7

Low range & low split - Large Reduction
Low range & high split - Small Reduction
High range & low split - Smaller Reduction
High range & high split - Direct

401Db

Question 8

What type of lubrication is most common on transmission?

Answer 8

Splash

401Db

Question 9

To aid a splash lubricated transmission, what is used to direct oil to critical areas of the transmission?

Answer 9

• Galleries cast in the housing
• Bolt-on troughs

401Db

Question 10

How is oil in a splash lubricated transmission filtered?

Answer 10

• Magnetic drain plugs
• Magnets on bottom of the housing

401Db

Question 11

What would operating the transmission with a high oil level cause?

Answer 11

• Foaming oil or overheating
• Air boubles would result in lack of lubrication and bearing or gear failure

401Db

Question 12

What drives the transmission oil pump?

Answer 12

Countershaft PTO gear
Driven whenever the input shaft is turning

401Db

Question 13

Where is the transmission filter generally located?

a) between cooler and transmission on return line
b) between pump and cooler on outlet line
c) between suction screen and pump

Answer 13

b) between pump and cooler on outlet line

401Db

Question 14

What weight of oil is used in Eaton transmissions?

Answer 14

SAE 50

401Db

Question 15

what is a mild hybrid vehicle

Answer 15

a vehicle that assists in the acceleration of take-off of a vehicle

Question 16

What is a full hybrid vehicle?

Answer 16

• Assists in acceleration on take-off
• Propel the vehicle without any input from the engine durring normal driving

401Db

Question 17

What is a mild hybrid vehicle?

Answer 17

Assists in acceleration on take-off only

401Db

Question 18

What are the two types of hybrid architectures?

Answer 18

Series
- Engine never directly drives the drivetrain

Parallel
- Engine, electric motor, or hydraulic motor are all capable of driving drivetrain

401Db

Question 19

What are the defining traits of a series hybrid drivetrain?

Answer 19

The engine never directly powers the vehicle.
Connected in series with a device that provides the power to propel the vehicle.

401Db

Question 20

What are the defining traits of a parallel hybrid drivetrain?

Answer 20

The electric motor or hydraulic pump is mounted between engine and transmission.
The engine or the electric or hydraulic motor are all capable of driving the transmission and propelling the vehicle.

401Db

Question 21

What are the two main functions of a motor/generator?

Answer 21

• Used as a motor to propel the vehicle
• Used as a generator to charge the batteries when regenerative braking

401Db

Question 22

What are the three main components of a diesel parallel electric hybrid?

Answer 22

• Motor/generator
• Inverter
• Power electronics carrier (PEC)

401Db

Question 23

What are the main purposes of the inverter in a hybrid vehicle?

Answer 23

• Convert DC to AC for propel mode
• Convert AC to DC during regenerative braking to charge the batteries

401Db

Question 24

What is the PEC in a hybrid vehicle?

Answer 24

Power Electronic Carrier
- Contains high voltage batteries
- Relay box
- Cooling fan and filter

401Db

Question 25

What type of batteries are prefered in electric hybrid vehicles due to their low self-discharge rates?

a) nickel–metal hydride (NiMH)
b) lithium-ion (Li-ion)
c) lithium iron phosphate (LiFePO4)
d) nickel–cadmium (NiCd)

Answer 25

b) lithium-ion

401Db

Question 26

In a diesel electric hybrid, what color are the high voltage cables?

Answer 26

Orange

401Db

Question 27

What is the minimum time to wait for the accumulators to bleed down after a vehicle shut off?

Answer 27

5 minutes

401Db

Question 28

When the operator releases the accelerator on a Hydraulic Launch Assist, the hydraulic motor and accumulator assist in slowing down the vehicle.
What can the operator do to bypass this feature and allow the vehice to coast?

Answer 28

Keep the accelerator slightly depressed about 10%

401Db

Question 29

What is the required buffer zone to establish when working on an electric hybrid vehicle?

Answer 29

1m or 3’

401Db

Question 30

What are worn on technician’s hands to protect them from high voltage?

Answer 30

• Inner rubber protective gloves
• Outer leather gloves

401Db

Question 31

A three-speed auxiliary section provides how many usable gears?

Answer 31

12 usable gears

401Db