Automatic Transmissions
Even the most efficient torque converter has a slippage rate of ________.
8% to 12%
During which of these conditions is the torque converter clutch engaged?
At speeds over 25 MPH
Using a torque converter smaller than stock size could result in ________.
Both B and C
Technician A says ATF is used to cool, clean, and lubricate an automatic transmission. Technician B says ATF is used to operate the shift valves, and transmit engine torque. Who is correct?
Both technicians
Technician A says most transmission hydraulic valves are spool valves. Technician B says the recessed areas of a spool valve are called grooves. Which technician is correct?
Both technicians
Technician A says that a held member is also called the reaction member. Technician B says that if any two elements are locked together then the output will be 1:1. Which technician is correct?
Both technicians
Technician A says that converter speed ratio is a measure of coupling efficiency. Technician B says that converter speed ratio is calculated by dividing the speed of the turbine rotation by the speed of the pump rotation. Which technician is correct?
Both technicians
Technician A says that hydraulic pressure affects transmission shift points. Technician B says that hydraulic pressure affects the feel of transmission shifts. Which technician is correct?
Both technicians
Technician A says that most pressure regulating valves work by balancing hydraulic pressure against a spring force. Technician B says that electronic transmissions use solenoids to further regulate hydraulic pressure. Which technician is correct?
Both technicians
Technician A says that one planetary gear set can provide gear reduction, overdrive, and reverse. Technician B says that most transmissions today use compound (multiple) planetary gear sets. Which technician is correct?
Both technicians
Technician A says that shift solenoids are used on some transmissions to control upshifts and downshifts. Technician B says that governor pressure is used on some transmissions to control upshifts and downshifts. Who is correct?
Both technicians
Technician A says that the automatic transmission/transaxle fluid (ATF) cooler is designed to cool the automatic transmission fluid. Technician B says that the cooler also warms the ATF when the fluid is cold. Which technician is correct?
Both technicians
Technician A says that the governor is used to measure vehicle speed in a hydraulically-controlled automatic transmission. Technician B says that the difference between hydraulically controlled and electronically controlled automatic transmissions is the way that the shift points are controlled. Which technician is correct?
Both technicians
Technician A says that the mainline pressure is usually higher in manual first gear than it is when the gear selector is in the drive position. Technician B says that mainline pressure is higher in reverse than when the gear selector is in the drive position. Which technician is correct?
Both technicians
Technician A says that the throttle position is an input to the PCM. Technician B says that the brake pedal switch is an input to the PCM. Which technician is correct?
Both technicians
Technician A says that when an automatic transmission/transaxle shifts into overdrive, the output shaft is rotating faster (higher RPM) than the engine crankshaft. Technician B says that an overdrive ratio is a ratio where the first number is less than 1. Which technician is correct?
Both technicians
Technician A says the default or limp-in gear is usually second or third gear. Technician B says that a transmission clutch, band, and solenoid chart shows the technician what is being applied in each gear. Which technician is correct?
Both technicians
Technician A says the gears in a planetary gearset are in constant mesh. Technician B says a planetary gearset has a ring gear and pinion gears. Which technician is correct?
Both technicians
Two technicians are discussing automatic transmission/transaxle oil pumps. Technician A says that a vane-type pump is a positive displacement pump. Technician B says that the pump is driven by the torque converter. Which technician is correct?
Both technicians
Two technicians are discussing one-way clutches. Technician A says that a sprag and a roller are two types of one-way clutches. Technician B says that a one-way clutch could be installed upside down and cause the automatic transmission/transaxle to not function correctly. Which technician is correct?
Both technicians
Which of these is the most current version of GM's Dexron ATF?
Dexron VI
How much is engine torque increased or multiplied when a typical torque converter is at stall speed?
Double
One clutch in a dual clutch transmission is used for 1st, 2nd, and 3rd gears and the other clutch is used for 4th, 5th, and 6th gears.
False
What is the purpose and function of a lock-up part of the torque converter?
Improves fuel economy by eliminating slippage
Which compound gearset uses a planetary gearset in front of a Ravigneaux gearset?
Lapelletier gearset
Which compound planetary gearset is commonly used in six speed transmissions?
Lapelletier gearset
Which valve is controlled by the position of the gearshift selector?
Manual
Force motors are controlled by the computer by ________.
PWM
What part controls mainline pressure in an electronically shifted automatic transmission?
Pressure control solenoid (force motor)
Technician A says automatic transmissions can shift gears without requiring an interruption of powerflow. Technician B says automatic transmissions use synchronizers instead of planetary gearsets. Which technician is correct?
Technician A only
Technician A says the torque converter pump is attached to the engine and turns as the engine rotates. Technician B says the turbine is attached to the engine and turns as the engine rotates. Which technician is correct?
Technician A only
Two technicians are discussing automatic transmissions/transaxles. Technician A says that it is normal for a vehicle to move slightly when the gear selector is in the "drive" position with the brakes released. Technician B says that the stator may be defective if the vehicle moves while in gear when the engine is at idle speed. Which technician is correct?
Technician A only
Technician A says electronic transmissions control shifts by directing the shift solenoid output pressure to the bands and clutches. Technician B says electronic transmissions control shifts by directing the shift solenoid output pressure to the shift valves. Who is correct?
Technician B only
Technician A says that all dual clutch automatic transmissions use two dry clutches. Technician B says that some automatic transmissions do not use planetary gear sets. Which technician is correct?
Technician B only
Technician A says that the transmission hydraulic pump operates only when the vehicle is in motion. Technician B says that the transmission hydraulic pump operates when the engine is running. Which technician is correct?
Technician B only
What is the purpose and function of an accumulator?
To cushion or dampen pressure surges
A CVT uses 2 pulleys and a drive chain to change gear ratios.
True
A CVT-type transaxle uses a ________ instead of planetary gear sets.
belt and pulley system
Automatic transaxles include a ________ in addition to the planetary gear sets.
differential assembly
A CVT changes gear ratios by changing the diameter of the ________.
drive and driven pulleys
The torque converter clutch increases efficiency by ________.
eliminating converter slippage
A TFT sensor measures ________.
fluid temperature
The major types of oil pumps used in an automatic transmission are ________.
gear, vane, and gerotor
A dual-clutch transmission may use wet clutches when used in ________ applications.
high-power
All current-model automatic transmissions are designed to use ________.
highly-friction modified ATF
Torque converters use a stator as a ________.
reaction member
Late model vehicles use ________ to change gear ratios in the automatic transmission.
solenoids
The steel plates in a clutch pack are commonly called ________.
steels