401e Transmission Shifting

Question 1

An auxiliary section that only has a range shift could have a gear ratio change as
much as ________________________ % from one shift to the next.

Answer 1

30 to 40%

Question 2

An auxiliary section that only has a splitter shift could have a gear ratio change as
much as ________________________ % from one shift to the next.

Answer 2

15 to 20%

Question 3

Combinations of range, splitter and deep reduction can be used to provide the operator with many gear positions.
T/F

Answer 3

True

Question 4

The main supply line must be properly routed and secure to prevent:
(2)

Answer 4

• damage from foreign objects

- becoming a moisture trap

Question 5

The air filter/regulator generally regulates air to ______________________ pressure.

Answer 5

58 to 63 psi (400 to 435 kPa)

Question 6

The master air control valve is not specific to each transmission to ease the number of parts in inventory.
T/F

Answer 6

false; The master air control valve is specific to each speed of transmission (that is, 13 speed and 18 speed).

Question 7

What is the purpose of the slave valve?

Answer 7

The slave valve allows the operator to pre-select the range shift by inhibiting the shift until the main section is in neutral

Question 8

While the main section is in gear, the slave valve piston is kept from moving by the:

a) actuating pin.
b) detent ball.
c) spring-loaded plunger.
d) master control valve.

Answer 8

a) actuating pin.

Question 9

The range cylinder is a double acting cylinder that uses a spring to hold it in the low position and air to shift it into the high position.
T/F

Answer 9

false; The range cylinder is a double acting cylinder that uses air to shift in both directions.

Question 10

The splitter/deep reduction air cylinder assembly is shifted:

a) when air from the master control valve is directed from one side of the piston to the other.
b) when air from the filter/regulator is directed to one side of the piston to the other.
c) when the slave valve sends air to one side of the piston or the other.
d) when air from the filter/regulator is directed to, or exhausted from, the back side of the piston.

Answer 10

d) when air from the filter/regulator is directed to, or exhausted from, the back side of the piston.

Question 11

The plastic air lines used in the multiple countershaft transmissions:

a) carry air to the master control valve.
b) carry air to the slave and/or spool valve.
c) are connected with ferrule/insert type fittings.
d) all of the above.

Answer 11

d) all of the above.

Question 12

The rubber coated cloth braid hoses carry large volume of air needed to quickly complete the range shift.
T/F

Answer 12

true

Question 13

Explain why a transmission manufacturer would develop a semi-automatic transmission where only the top two gears are automatically selected.

Answer 13

The top two gears are the gears used most in some vehicle applications. Having these shifted automatically, reduces the operator workload considerably.

Question 14

On the semi-automated transmissions, the electronically controlled shift system is controlled by the:

a) transmission electronic control unit.
b) shift tower electronic control unit.
c) engine electronic control unit.
d) all of the above.

Answer 14

c) engine electronic control unit.

Question 15

Explain why the semi-automated transmission is left in the high splitter position when it is shifted into the auto position.

Answer 15

Leaving the splitter in the high position makes it easier for the operator when shifting out of the auto position back into 7th.

Question 16

Identify four (4) system components used in the electronic controlled shift systems.

Answer 16

Any four (4) of the following are correct.

• shift controller (electronic control unit and operator console)
• visual display panel
• transmission controller (electronic control unit)
• X – Y shifter (main section electric shift assembly)
• shaft speed sensors
• range and/or splitter assembly
• inertia brake
• wiring harness

Question 17

The transmission shift controller contains:

a) electronic control unit and dash display.
b) electronic control unit and operator shift console.
c) operator shift console and dash display.
d) main section electric shifter and range/splitter assemblies.

Answer 17

b) electronic control unit and operator shift console.

Question 18

The dash display is an output device that informs the operator of the state of the shifting process by the use of:

a) arrows.
b) numbers.
c) letters.
d) all of the above.

Answer 18

d) all of the above.

Question 19

The component responsible for all of the transmission shifting operations is the:

a) transmission controller.
b) shift controller.
c) main section electric shift assembly.
d) engine electronic control unit.

Answer 19

a) transmission controller.

Question 20

The rail motor moves the shift finger along the shift shaft to the desired rail by rotating the rail yoke.
T/F

Answer 20

false; When signalled by the transmission controller, the rail motor moves the shift finger along the shift shaft to the desired shift rail through a slotted connection between the rail nut and shift finger.

Question 21

The range and splitter shifting is done through:

a) electronically controlled solenoids that move the shafts.
b) electronically controlled electric-over-air solenoids.
c) electronically controlled reversible DC motors.
d) an air signal from the master control valve.

Answer 21

b) electronically controlled electric-over-air solenoids.

Question 22

The purpose of the inertia brake is to:

a) increase the rate of deceleration of the countershafts.
b) decrease the rate of deceleration of the countershafts.
c) increase the rate of deceleration of the mainshaft.
d) decrease the rate of deceleration of the mainshaft.

Answer 22

a) increase the rate of deceleration of the countershafts.

Question 23

Which mode must the operator select to have manual control of both upshifting and downshifting?

a) drive
b) low
c) hold
d) direct

Answer 23

c) hold

Question 24

Which mode selection would the operator use to get maximum engine braking?

a) drive
b) low
c) hold
d) default

Answer 24

b) low

Question 25

The operator must always disengage the clutch (depress the clutch pedal) when starting the vehicle in case the vehicle was shut off while in a gear other than neutral or there is a short or ground fault in the neutral safety switch circuit.
T/F

Answer 25

false; Whenever the vehicle is shutdown, the shift controller and the transmission controller will not power down immediately, but go through a shutdown procedure placing the transmission in neutral. The start enable relay is used by the automated transmission to prevent the truck from being started without first verifying that the transmission is in neutral.

Question 26

During normal operation in Drive, the shift controller co-ordinates the shift by communicating with the transmission controller and the engine ECU.
T/F

Answer 26

true

Question 27

If the operating conditions of the transmission change, a new program must be installed in the shift controller through a PC based diagnostic tool.
T/F

Answer 27

false; The automated transmission has the ability to learn and adapt the shift points as the vehicle load conditions change. The operator can help the electronic control system learn to use new shift points during the shifting process.

Question 28

List the three (3) data links used in the automated transmission electronic system.

Answer 28

• proprietary data link
• SAE standard J-1939
• SAE standard J-1587

Question 29

List the three (3) ways that the diagnostic fault codes can be retrieved.

Answer 29

• service warning light on the shift console
• scan tools
• PC based diagnostic equipment