Deck 17: Torque Converters

Question 1

Technician A says that a torque converter is a type of fluid coupling.Technician B says that because a torque converter makes no direct mechanical connection between the engine and transmission,some loss of torque output results when the unit is not in lock-up mode.Who is correct?

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

Answer 1

C

Question 2

Technician A says that when it is necessary to rebuild a torque converter stator assembly,it should be removed first.Technician B says that cracked stator vanes can be TIG welded.Who is correct?

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

Answer 2

A

Question 3

In which of the following phases of torque converter operation will torque be multiplied?

A) lock-up
B) vortex flow
C) rotary flow
D) freewheel

Answer 3

B

Question 4

Where is a flex plate located?

A) between the crankshaft and the flywheel
B) between crankshaft and torque converter
C) between the turbine and output shaft
D) between torque converter and transmission

Question 5

Which of the following does most to determine the power output of a torque converter?

A) engine rated power
B) engine rpm
C) transmission ratio
D) driveline propeller shaft rpm

Question 6

A flex plate can also be known as a flex ....:

A) disc
B) rotor
C) wheel
D) shaft

Question 7

When is vortex flow at its maximum during torque converter operation?

A) full turbine stall
B) under heavy acceleration
C) at the end of coupling phase
D) at the beginning of lock-up

Question 8

What type of stator tends to be found in heavy-duty truck torque converters?

A) fixed
B) rotating
C) variable pitch
D) tandem

Question 9

Technician A says that during the coupling phase,the impeller and turbine should be turning within 10% of the same speed.Technician B says that the only time that the impeller and turbine turn at exactly the same speed is when the lock-up clutch is engaged.Who is correct?

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

Question 10

What is another term used to describe the impeller used on a torque converter?

A) turbine
B) compressor
C) pump
D) stator

Question 11

Which of the following should always rotate at engine crankshaft speed?

A) impeller
B) turbine
C) stator
D) lock-up clutch

Question 12

Which of the following components can be used to transfer engine crankshaft torque to the torque converter assembly?

A) overrunning clutch
B) flex plate
C) stator
D) turbine

Question 13

Which of the following is the output or driven member of a torque converter assembly?

A) stator
B) turbine
C) flex plate
D) impeller

Question 14

Technician A says that all heavy-duty trucks with automatic transmissions use centrifugal lock-up converters.Technician B says that a centrifugal lock-up clutch consists of a piston,clutch plate,and back plate.Who is correct?

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

Question 15

At what pressure should shop air be regulated to test a weld-sealed torque converter?

A) 5 psi
B) 25 psi
C) 75 psi
D) 100 psi

Question 16

When will torque multiplication be the greatest?

A) pump and turbine rpm is equal
B) greatest difference between pump and turbine rpm
C) when engine rpm is highest
D) when lock-up clutch engages

Question 17

Technician A says that torque converters with welded halves are not designed to be field serviceable.Technician B says that some Allison torque converter are designed to be serviceable.Who is correct?

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

Question 18

What usually connects a torque converter turbine to the transmission input shaft?

A) hydraulic fluid
B) splines
C) internal spur gear teeth
D) weld

Question 19

Technician A says that when a torque converter flex plate is used,a flywheel is never required.Technician B says that when a flex plate is used,the starter motor pinion engages with teeth on the converter housing.Who is correct?

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

Question 20

In torque converter operation,when does the stator start to freewheel?

A) during torque multiplication phase
B) at the beginning of coupling phase
C) at the end of turbine lock-up phase
D) at the beginning of impeller stall

Question 21

When a torque converter impeller and turbine speeds match during normal operation,which one of the following must be true?

A) coupling phase
B) lock-up phase
C) peak torque multiplication
D) seized stator

Question 22

Technician A says that vortex flow is at its maximum at full stall.Technician B says that vortex flow is at a minimum during coupling phase.Who is correct?

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

Question 23

Technician A says that in any type of fluid coupling not equipped with a mechanical lock-up some slippage exists resulting in a difference between input and output speeds.Technician B says that in torque converter coupling phase impeller and turbine rpms match.Who is correct?

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

Question 24

Which of the following components is locked to the front cover of a torque converter during the lock-up phase and not otherwise?

A) impeller
B) stator
C) overrunning clutch
D) turbine

Question 25

Technician A says that when the lock-up clutch is engaged on a torque converter,the coupling ratio between the impeller and turbine has to be 1:1.Technician B says at the fluid coupling point in a torque converter,the impeller and turbine must be rotating at exactly the same speed.Who is correct?

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

Question 26

Which of the following is a key difference between a torque converter and other types of fluid couplings?

A) curved versus straight blades
B) type of transmission fluid used
C) type of turbine used
D) straight versus helical input shaft splines

Question 27

When the impeller and turbine speeds are turning within 10% of each other,this is known as:

A) lock-up phase
B) coupling phase
C) vortex flow
D) stall phase

Question 28

What should be used to check endplay when inspecting a torque converter assembly?

A) thickness gauges
B) endplay gauge and dial indicator
C) screwdriver and depth micrometer
D) machinist level and plastigage

Question 29

When the direction of oil flow in the stator is the same as that in both the impeller and the turbine,this is known as:

A) rotary flow
B) vortex flow
C) full stall
D) stator lock

Question 30

Technician A says that a torque converter stator has a direct mechanical connection to the impeller.Technician B says that a torque converter stator has a direct mechanical connection with the turbine.Who is correct?

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