Chapter 8 Answers to Review Questions

CLASSROOM MANUAL, PAGES 277-279

Short Answer Essays

1.If any two of the planetary gearset members receive power in the same direction and at the same speed, the third member is forced to move with the other two and direct drive results.

2.The input shaft connects the output of the torque converter to the driving members inside the transmission. The output shaft connects the driven member of the gearsets to the final drive gearset.

3.There are two common designs of compound gearsets: the Simpson gearset, in which two planetary gearsets share a common sun gear, and the Ravigneaux gearset, which has two sun gears, two sets of planet gears, and a common ring gear.

4.If the planet carrier is held and the sun gear is rotated in a clockwise rotation, the ring gear will rotate in a counterclockwise direction. The planet gears cannot travel around the teeth of an enmeshed gear; rather, the carrier is held in place and the planet gears spin on their shafts. The sun gear spins the planet gears, which drive the ring gear in the opposite direction but at a slower speed. Therefore the gearset is providing reverse gear with reduction.

5.Gear reduction is accomplished in a planetary gearset by holding the sun gear. If power is applied to the ring gear, the planet gears will spin on their shafts in the planet carrier. Because the sun gear is being held, the spinning planet gears will walk around the sun gear and carry the planet carrier with them; this causes a gear reduction. Gear reduction can also occur if the ring gear is held and the sun gear is the input gear. The planet carrier rotates around the sun gear, but turns more slowly than it did when the ring gear drove the planet carrier.

6.As the vehicle goes around a corner, the inside wheel travels a shorter distance than the outside wheel. The inside wheel must therefore rotate more slowly than the outside wheel. An equal percentage of speed is removed from one axle and given to the other; however, an equal amount of torque is applied to each wheel.

7.A transfer case divides transmission output to the two different drive axles to provide for four-wheel drive.

8.These transaxles have a main shaft and countershaft on which the gears ride. The two shafts run parallel to each other, and some later models have a third parallel shaft. To provide the forward gears and one reverse gear, different pairs of gears are locked to the shafts by hydraulically controlled clutches. Reverse gear is obtained, on some models, through the use of a shift fork that slides the reverse gear into position. The power flow through these transaxles is also similar to that of a manual transaxle.

9.When there is input into a planetary gearset but a member is not held, neutral results.

10.When two gearsets are in tandem, the front ring gear is normally connected to the rear carrier and the rear ring gear is connected to the front carrier.

Fill-in-the-Blanks

1.External, internal

2.Sun, ring

3.Direction, speed, direct

4.Sun gear, planetary carrier, ring gear

5.Annulus, internal

6.Increased, decreased

7.Planet carrier

8.Interaxle

9.Planet, ring, sun

10.Sun, planet, ring

Multiple Choice

1.B

2.B

3.D

4.D

5.C

6.A

7.C

8.C

9.C

10.C

SHOP MANUAL, PAGES 353-354

ASE-Style Review Questions

1.A

2.C

3.C

4.B

5.C

6.B

7.C

8.C

9.B

10.D

ASE Challenge Questions

1.B

2.D

3.C

4.C

5.A

Instructor’s Guide to Accompany Today’s Technician: Automatic Transmissions & Transaxles 3E1