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

Accepted Answer

Both statements are correct. A torque converter is indeed a type of fluid coupling that transfers rotating power from a prime mover, like an internal combustion engine, to a rotating driven load. It does this using a fluid hydrodynamic process, which means there is no direct mechanical connection between the engine and the transmission, leading to some loss of torque output when the unit is not in lock-up mode, as stated by Technician B.

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

Accepted Answer

Technician A is correct because the stator assembly must indeed be removed for a rebuild. Technician B's suggestion to TIG weld cracked stator vanes is not advisable as it could compromise the integrity and balance of the stator, leading to potential failure.

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

Accepted Answer

Torque multiplication occurs during the vortex flow phase of a torque converter's operation. This is when the engine's input and the converter's output speeds differ significantly, allowing the converter to multiply the input torque before sending it to the transmission.

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

Accepted Answer

A flex plate is located between the crankshaft and the torque converter in vehicles with automatic transmissions, connecting these two components to transmit engine power to the 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

Accepted Answer

The power output of a torque converter is primarily determined by the engine rpm.

Question 6

A flex plate can also be known as a flex ....:
A) disc
B) rotor
C) wheel
D) shaft

Accepted Answer

A flex plate is also known as a flex disc, which is a component used to connect the transmission to the engine in vehicles, particularly in automatic transmission systems.

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

Accepted Answer

During full turbine stall, the relative motion between the turbine and impeller is at its maximum, creating the highest vortex flow within the torque converter.

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

Accepted Answer

Rotating stators are commonly used in heavy-duty truck torque converters because they provide a more efficient transfer of torque than fixed stators.

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

Accepted Answer

During the coupling phase of a torque converter, the impeller and turbine do indeed turn at speeds that are close to each other, but not necessarily within 10% as Technician A suggests. However, Technician B is correct in stating that the impeller and turbine turn at exactly the same speed only when the lock-up clutch is engaged, which bypasses the fluid coupling entirely, creating a direct mechanical connection between the engine and the transmission. Therefore, both technicians are correct in the context of their statements about the operational characteristics of a torque converter and its lock-up clutch.

Question 10

What is another term used to describe the impeller used on a torque converter?
A) turbine
B) compressor
C) pump
D) stator

Accepted Answer

The impeller in a torque converter is also known as the pump. It is responsible for moving transmission fluid to the turbine and stator.

Question 11

Which of the following should always rotate at engine crankshaft speed?
A) impeller
B) turbine
C) stator
D) lock-up clutch

Accepted Answer

The impeller is directly connected to the engine crankshaft and rotates at the same speed.

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

Accepted Answer

The flex plate is directly bolted to the engine's crankshaft and serves to transfer the rotational torque of the crankshaft to the torque converter assembly in automatic transmissions.

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

Accepted Answer

The turbine is the output or driven member of a torque converter assembly, as it is connected to the transmission's input shaft, receiving torque from the fluid movement initiated by the 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

Accepted Answer

Not all heavy-duty trucks with automatic transmissions use centrifugal lock-up converters, and a centrifugal lock-up clutch does not typically consist of a piston, clutch plate, and back plate.

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

Accepted Answer

The answer of At what pressure should shop air be...

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

Accepted Answer

Torque multiplication is greatest when there is the greatest difference between the pump and turbine rpm in a torque converter, as this difference allows the torque converter to multiply the engine's torque more effectively.

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

Accepted Answer

Technician A is correct because torque converters with welded halves are indeed not designed to be opened and serviced in the field; they are typically replaced as a unit. Technician B is also correct because some Allison torque converters are designed to be serviceable, allowing for maintenance and repair without complete replacement.

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

Accepted Answer

Splines are typically used to connect a torque converter turbine to the transmission input shaft, allowing for a secure mechanical connection that can transmit the rotational force efficiently.

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

Accepted Answer

Technician A is correct in stating that a flywheel is not required when a torque converter flex plate is used, as the flex plate serves a similar purpose in automatic transmissions. However, Technician B is incorrect because the starter motor pinion engages with teeth on the flex plate itself, not on the converter housing.

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

Accepted Answer

The stator starts to freewheel at the beginning of the coupling phase, as its role in torque multiplication is no longer needed, allowing the impeller and turbine to rotate at nearly the same speed.

Quiz 17: Torque Converters

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?

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?

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

Where is a flex plate located?

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

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

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

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

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?

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

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

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

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

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?

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

When will torque multiplication be the greatest?

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?

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

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?

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