CH 23 Transmissions

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.

False

Which of the following describe the operation of the hydraulic control system and the gear train in an automatic transmission?

a. Selecting and shifting gear ratios to match road speed and engine load without driver input

Which of the following are a friction type of bearing similar to engine main bearings.

a. Thrust washers

Tech A says bands are applied by applying fluid pressure to a servo. Tech B says a servo piston is typically sealed with a square-cut seal. Who is correct?

b. Both A and B

Tech A says that the torque converter multiplies the amount of torque transmitted from the engine to the transmission. Tech B says that the torque converter couples and uncouples the engine and transmission as the vehicle stops and starts in traffic. Who is correct?

b. Both A and B

Which of the following can be either roller or sprag design?

b. One-way clutches

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?

b. Stall speed

Technician A says a multi-disc clutch is a holding/application device in an automatic transmission. Technician B says a one-way roller or sprag is a device that typically drives another component in an automatic transmission. Who is correct?

b. Technician A

Inside a torque converter, the one-way clutch allows the stator to rotate only in one direction. Technician A says that it will turn in the same direction as the output shaft. Technician B says it turns in the same direction as the impeller. Who is correct?

b. Technician B

The transmission needs to be able to adapt the engine torque to meet the ______________ demands of the vehicle.

b. speed and power

What are Torrington bearings?

c. A needle or roller type, thrust bearing

Tech A says planetary gear sets use either helical- or straight-cut gears. Tech B says bands, multi-disc clutches, and one-way clutches are the three basic holding devices used to lock a planetary member to the transmission case. Which tech is correct?

c. Both A and B

Tech A says that a transaxle must have a type of differential assembly to allow the front wheels to turn at different speeds while driving around a curve. Tech B says that a conventional rear-wheel drive vehicle will typically use a differential assembly that is located in the rear axle assembly. Who is correct?

c. Both A and B

Tech A says transaxles include a differential and final drive gear to an automatic transmission. Tech B says dual-clutch transmissions use two clutches instead of a standard torque converter. Who is correct?

c. Both A and B

When a servo applies pressure to one end of the band, how does it hold the planetary member?

c. The band contracts around the brake drum

Technician A says a servo-operated band can only hold a member stationary in an automatic transmission. Technician B says multi-disc clutches can hold or drive individual members of the planetary set in an automatic transmission. Who is correct?

d. Both A and B

Which of the following is used increase fuel economy and prevent heat generation in the torque converter?

d. Lockup clutch

Technician A says sometimes servos can be accessed from the outside of the transmission. Technician B says you have to remove the transmission to access the servos. Who is correct?

d. Technician A

Automatic transmissions are designed to prevent a downshift if that downshift would cause the engine to exceed the safe maximum RPM.

true

In the operation of a servo, fluid under pressure is directed onto one side of the piston in the closed cylinder, moving it to apply the band.

true

Reverse requires greater clutch and brake holding force, so the manual valve will direct additional fluid to work with the pressure regulator valve spring, increasing line pressure.

true

The benefit of designing transmissions with planetary gears is that if you need more gear ratios than you have, you can combine multiple planetary gear sets to create the needed ratios.

true

The front pump bushing is used to support the torque converter and sees the largest amount of wear in the transmission because it is in use anytime the engine is running.

true

The gears inside a conventional automatic transmission are constantly meshed to each other.

true

The planetary gear set has a sun gear in the center with smaller planetary gears revolving around the sun gear.

true