Deck 9: Torque Converter Principles

Question 1

When rebuilding a transmission, most shops will:

A) flush out the old torque converter.
B) reinstall the old torque converter if there were no issues with the old one.
C) replace with a rebuilt torque converter.
D) rebuild the torque converter in-house.

Answer 1

C

Question 2

A torque converter has the main benefit over a manual transmission of:

A) torque multiplication.
B) extra cooling.
C) manual control of the disengagement of the transmission.
D) reduced weight.

Answer 2

A

Question 3

A torque converter does all of the following except:

A) enables the transmission to automatically couple and uncouple from the engine when needed.
B) allows the engine to idle at a stop, even though the transmission is still in gear.
C) multiplies torque from the engine to the input shaft of the transmission under certain driving conditions.
D) transmits lower amounts of torque as engine speed increases.

Answer 3

D

Question 4

When there is a large difference between the speed of the impeller and the turbine:

A) maximum torque multiplication occurs.
B) the vehicle is at rest.
C) torque multiplication falls to zero.
D) fluid flow from the turbine vanes is relatively low.

Question 5

Tech A says that the impeller is splined to the input shaft. Tech B says that the stator is fixed solidly to the torque converter housing. Who is correct?

A) Tech A
B) Tech B
C) Both A and B
D) Neither A nor B

Question 6

Tech A says that the torque converter can multiply the amount of torque transmitted from the engine to the transmission. Tech B says that the torque converter allows the engine to idle when the vehicle stops in traffic. Who is correct?

A) Tech A
B) Tech B
C) Both A and B
D) Neither A nor B

Question 7

The purpose of the stator in a torque converter is to:

A) prevent fluid leaks.
B) allow torque multiplication.
C) improve fuel economy.
D) lock up the turbine during cruise conditions.

Question 8

Tech A says that the torque converter hub drives the front pump in an automatic transmission. Tech B says that the turbine shaft drives the front pump. Who is correct?

A) Tech A
B) Tech B
C) Both A and B
D) Neither A nor B

Question 9

Stall speed is defined as:

A) the speed at which the engine will shut fuel off.
B) the maximum speed difference between the impeller and turbine in the torque converter.
C) the speed at which the lock up torque converter will cause the engine to stall.
D) the maximum difference in speed between the input shaft of the transmission and the output shaft.

Question 10

The average torque multiplication for a torque converter in a passenger car is:

A) 1.5:1.
B) 1.8:1.
C) 2.2:1.
D) 2.5:1.

Question 11

Tech A says that the front pump only operates when the turbine is rotating. Tech B says that a torque converter clutch locks the turbine to the converter housing when applied. Who is correct?

A) Tech A
B) Tech B
C) Both A and B
D) Neither A nor B

Question 12

Tech A states that torque converters are completely filled with transmission fluid during operation. Tech B states that torque converters push air around inside like a fan. Who is correct?

A) Tech A
B) Tech B
C) Both A and B
D) Neither A nor B

Question 13

Torque converters create excess heat that must be removed by:

A) transmission cooler in the radiator.
B) external cooler.
C) deep finned oil pans.
D) All of the above

Question 14

What is achieved when the transmission fluid first runs through the external cooler and then through the cooler in the radiator?

A) It increases the viscosity of the transmission fluid.
B) It prevents overcooling of the transmission fluid.
C) It draws heat away from the fluid in the transmission pan.
D) It prevents overheating of the transmission fluid.

Question 15

Tech A states that it is important to keep transmission fluid temperature as low as possible. Tech B states that transmission fluid must be kept about 230 degrees for optimum operation. Who is correct?

A) Tech A
B) Tech B
C) Both A and B
D) Neither A nor B

Question 16

Lock-up torque converters are controlled by:

A) hydraulic valves.
B) electric motors.
C) hydraulic valves and electric solenoids.
D) centrifugal force.

Question 17

Tech A states that lock up torque converters are either fully applied or fully released. Tech B states that many manufacturers will pulse the torque converter on to prevent harsh application. Who is correct?

A) Tech A
B) Tech B
C) Both A and B
D) Neither A nor B

Question 18

Tech A states that the torque converter should be replaced in the event of catastrophic transmission failure. Tech B states that it is possible to flush out the converter on a specialized flushing machine. Who is correct?

A) Tech A
B) Tech B
C) Both A and B
D) Neither A nor B

Question 19

Tech A states that lock up torque converters will set a trouble code when they fail. Tech B states that a failed lock up torque converter system may require the rebuild of the transmission. Who is correct?

A) Tech A
B) Tech B
C) Both A and B
D) Neither A nor B

Question 20

Tech A states that the stator is used to improve fuel economy in a torque converter. Tech B states that the stator is used to multiply torque in the torque converter. Who is correct?

A) Tech A
B) Tech B
C) Both A and B
D) Neither A nor B

Question 21

Most transmission shops do not rebuild torque converters due to the amount of time needed to perform the service.

Question 22

Technician A says that to properly service a torque converter, it must be cut apart using a special machinist lathe. Technician B says that a serviced torque converter must be welded together then pressure tested for leaks. Who is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 23

It is common for some torque converter rebuilders to replace every bushing during the rebuilding process.

Question 24

Technician A says that if loose turbine fins are found, they can be re-brazed to the housing or guide ring. Technician B says that if some fins are damaged, they will be straightened. Who is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 25

A torque converter should be balanced once reassembled and pressure tested.

Question 26

The torque converter friction material should be inspected and replaced if it shows all of the following EXCEPT:

A) wrong color
B) wear
C) burn marks
D) flaking material

Question 27

If friction material is to be reused, it is ok to clean it in a solvent tank.

Question 28

Technician A says the stator should be disassembled to test the one-way roller or sprag assembly. Technician B says that each roller should be inspected for scratches or signs of overheating. Who is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 29

Technician A says that a one-way roller that doesn't hold while turning in both directions is good to use for reassembly. Technician B says that once a one-way roller tests ok, it should be lubricated with any type of transmission fluid. Who is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 30

Which of the following are replacement choices for clutch friction materials?

A) Kevlar
B) Carbon
C) Teflon
D) Non-asbestos organic

Question 31

Technician A says that the torque converter should be replaced when rebuilding a transmission. Technician B says that if a converter is not replaced, it should be checked and flushed. Who is correct?
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A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 32

A torque converter on a transmission that suffered a catastrophic failure should always be replaced due to difficulty in removing all of the debris.

Question 33

A torque converter should always be replaced during rebuilding as the internal lock-up clutch may be worn.

Question 34

Torque converters should always be flushed using a specialized converter flushing machine.

Question 35

Technician A says that it is almost impossible to drain all of the fluid out of a converter. Technician B says that it is impossible to remove all of the old fluid and debris without a flushing machine. Who is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 36

Before reusing a torque converter, the end play should always be checked.

Question 37

Technician A says that a turbine tool is needed to test for converter end play. Technician B says that a pair of snap ring pliers can be used. Who is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 38

The amount of end play measured does not need to be compared to specifications.

Question 39

Technician A says that when measuring converter end play with a special tool, a dial indicator must always be used. Technician B says that when using snap ring pliers, a technician can usually judge the amount of end play with some practice. Who is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 40

A sticking brake light switch can cause a torque converter clutch to fail.

Question 41

When the torque converter clutch is engaged, what are the springs which dampen engine and drive line vibrations called?

A) Transmission support
B) Drive line torsional
C) Torsional damper
D) Torsional muffler

Question 42

What are the torsional springs in the lockup converter assembly designed to dampen?

A) Converter ballooning
B) Impeller vibrations
C) Shift harshness
D) Crankshaft power pulses

Question 43

Torsional damper springs are built into the torque converter clutch piston assembly.

Question 44

If the automatic transmission's shift linkage is not adjusted properly, the transmission position indicator will not be set correctly, the customer will not know which gear the vehicle is in, and the backup or reverse lights may not work.

Question 45

If this automatic transmission component is not adjusted properly, the vehicle may not start, or it may start in gear, resulting in a major safety hazard.

A) Shift linkage
B) Transmission range sensor
C) Lock-up torque converter
D) Both A and B

Question 46

Which of the following is a typical condition for torque converter lockup?

A) Heavy-load low speed
B) Light-load high speed
C) Idle
D) None of the above

Question 47

Technician A says early torque converters always have some slippage, so manufacturers added a lockup clutch to the torque converter. Technician B says typically, torque converter lockup will only happen when the vehicle is under an appropriate load and speed. Which technician is correct?

A) Technician A
B) Technician B
C) Both A and B
D) Neither A nor B

Question 48

Technician A says when servicing an automatic transmission, it is never necessary to adjust the shift linkage or range sensor. Technician B says an improperly adjusted shifter linkage and range sensor can cause the vehicle to not start. Who is correct?

A) Technician A
B) Technician B
C) Both A and B
D) Neither A nor B

Question 49

Which of the following describes conditions for torque converter lockup?

A) Heavy-load lower speed
B) Light-load higher speed
C) Heavy-load just starting up from a stop
D) Light-load just starting up from a stop

Question 50

In a lock-up converter the _______ and _______ are locked together, when conditions are suitable.

A) Impeller and Turbine
B) Impeller and Stator
C) Turbine and Stator
D) Turbine and Turbine shaft

Question 51

How does a lock-up converter obtain lock-up?

A) A one-way clutch locks the turbine and impeller at a certain rpm
B) The stator starts to free-wheel, locking the two parts together
C) The turbine rotates backwards locking it to the input shaft
D) A large piston is pressed against the front housing of the torque converter

Question 52

Technician A says early torque converters always had some slippage, so in the late 1970's and early 1980's, manufacturers added a lockup clutch to the torque converter. Technician B says typically, torque converter lockup will only happen when the vehicle is under an appropriate load and speed. Who is correct?

A) Technician A
B) Technician B
C) Both A and B
D) Neither A nor B

Question 53

Technician A says an improperly adjusted shift linkage and range sensor can cause the vehicle to start in gear. Technician B says an improperly adjusted shift linkage and range sensor can cause the vehicle to not start. Who is correct?

A) Technician A
B) Technician B
C) Both A and B
D) Neither A nor B

Question 54

Disconnect the _______ from the transmission when adjusting the linkage and/or range sensors.

A) Battery positive terminal
B) Steering linkage
C) Shift linkage
D) Starter motor

Question 55

Technician A states that if the transmission shift linkage is not adjusted properly, the transmission position indicator (PRNDL indicator) will not be set correctly. Technician B states that if the transmission shift linkage is not adjusted properly the backup or reverse lights may not work. Who is correct?

A) Technician A
B) Technician B
C) Both A and B
D) Neither A nor B

Question 56

What tool below is commonly used to check that the neutral safety switch/transmission range switch has continuity on the correct terminals?

A) Ohmmeter
B) Labscope
C) Ammeter
D) Voltmeter

Question 57

When servicing an automatic transmission, it may be necessary to adjust the _______ along with the transmission range sensor.

A) Sprag assembly
B) Line pressure
C) Transfer case fluid level
D) Shift linkage

Question 58

Technician A says powertrain mounts hold the engine and transmission in proper position in the vehicle. Technician B says a faulty powertrain mount cannot affect throttle linkage. Who is correct?

A) Technician A
B) Technician B
C) Both A and B
D) Neither A nor B

Question 59

A vehicle stalls when coming to a stop. After test-driving the vehicle, it is found that the Torque Converter Clutch (TCC) is remaining engaged as the vehicle slows down. Technician A says that the vehicle probably needs a new torque converter. Technician B says that the TCC solenoid may be sticking and could need replaced. Who is correct?

A) Technician A
B) Technician B
C) Both A and B
D) Neither A nor B

Question 60

The transmission fluid warmer assembly uses a thermostatic valve to direct the flow of transmission fluid depending on temperature. Which of the statements are True about how the thermostatic valve routes ATF?

A) Fluid is sent through the heated warmer assembly when the ATF is cold
B) Fluid is sent through the heated warmer assembly when the ATF is hot
C) Fluid bypasses the heated warmer assembly if the ATF is hot
D) Both A and C

Question 61

What happens to ATF when it becomes too hot?

A) It can produce cavitation bubbles in the fluid and reduce converter efficiency
B) It oxidizes or breaks down prematurely
C) It will shorten the life of the transmission fluid greatly
D) All of the above

Question 62

Transmission fluid is routed through a heat exchanger in the radiator which keeps the ATF at an ideal temperature: warming the fluid when it is cold and removing heat if it becomes too hot.

Question 63

When using an external transmission fluid cooler, the best practice is to run the transmission fluid through the external cooler first and then through the heat exchanger in the radiator.

Question 64

Which of the following is the typical routing of an external transmission fluid cooler?

A) The fluid cooler should be mounted before the radiator transmission heat exchanger
B) The fluid cooler should be mounted after the radiator transmission heat exchanger
C) The fluid cooler should be used to replace the radiator transmission heat exchanger
D) None of the above cooler routing is not important

Question 65

Two technicians are discussing transmission heat exchangers. Technician A says when installing an add-on cooler, you should plum the cooler so the transmission fluid goes through the add-on cooler before the radiator. Technician B says when installing an add-on cooler, you should plum the cooler so the transmission fluid goes through the radiator before the add-on cooler. Who is correct?

A) Technician A
B) Technician B
C) Both A and B
D) Neither A nor B

Question 66

Which of the following is the typical routing of an external transmission fluid cooler?

A) Cooler first then radiator
B) Radiator first then cooler
C) External coolers are installed to bypass the radiator
D) None of the above

Question 67

Two technicians are discussing transmission heat exchangers. Technician A says when installing an add-on cooler, you should plumb the cooler so the transmission fluid goes through the add-on cooler before the radiator. Technician B says when installing an add-on cooler, you should plum the cooler so the transmission fluid goes through the radiator before the add-on cooler. Who is correct?

A) Technician A
B) Technician B
C) Both A and B
D) Neither A nor B

Question 68

Technician A says that at stall speed, a lot of engine output is converted into heat that must be removed. Technician B says that excessive heat in transmission fluid can cause cavitation and fluid oxidation. Who is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 69

Technician A says that fluid flows from the cooler into the converter. Technician B says that fluid flows from the converter into the cooler. Who is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 70

With the engine idling, little torque is transferred from the impeller to the turbine, as the fluid flow is too slow.

Question 71

What unlocks the stator's one-way clutch, allowing the stator to rotate with the fluid?

A) The stator control solenoid
B) Fluid striking the back (convex side) of the stator blades.
C) An input shaft speed that is higher than the impeller spee
D) Fluid striking the front (concave side) of the stator blades.

Question 72

What happens when the stator is unlocked?

A) Vortex flow in the torque converter fluid is limited
B) Torque converter efficiency is reduced by preventing the stator from being in the way of the fluid flow
C) Torque multiplication in the torque converter is minimized or eliminated
D) Both A and C

Question 73

Stall is an operating condition where the turbine is stationary and the engine throttle is wide open, making the rotational speed of the impeller as high as possible.

Question 74

As the vehicle begins to move from a stop, torque multiplication is minimal because there is a large difference between the speed of the impeller and the turbine.

Question 75

When the turbine speed is less than about 90% of the impeller speed, the shape of the converter case makes the fluid flow in a circular motion, through the impeller, turbine, and stator. What does this create?

A) Overdrive
B) Torque Converter Clutch lockup
C) Torque multiplication
D) Speed multiplication

Question 76

Torque converter lockup normally occurs at lower road speeds and when the vehicle is under light load.

Question 77

What is the operating condition where the turbine is stationary and the engine throttle is wide open, making the rotational speed of the impeller as high as possible?

A) Torque speed
B) Stall speed
C) Slip speed
D) None of the above

Question 78

Typically, when turbine speed reaches 90% of impeller speed, what is the torque multiplication in the torque converter?

A) 1:01
B) 2.5:1
C) 4:01
D) None of the above

Question 79

Which of the following is a type of fluid flow in a torque converter?

A) Rotary flow
B) Vortex flow
C) Spiral flow
D) All of the above

Question 80

What is the operating condition called, where the turbine is stationary and the engine throttle is wide open, making the rotational speed of the impeller as high as possible?

A) Coupling speed
B) Stall speed
C) Red line
D) None of the answers listed