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 fourwheel 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
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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
Instructor’s Guide to Accompany Today’s Technician: Automatic Transmissions & Transaxles 3E
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3. C
4. C
5. A
Instructor’s Guide to Accompany Today’s Technician: Automatic Transmissions & Transaxles 3E
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