Chapter4manual Transmissions/Transaxles

Chapter4Manual Transmissions/Transaxles

Answers to Review Questions

•Classroom Manual, Pages 95–97

Short Answer Essays

1.The purpose of a transmission is to use different gear ratios to provide the engine with a mechanical advantage over the vehicle’s drive wheels.

2.The primary purpose of a synchronizer is to equalize the speed of a shaft and gears before they are engaged in order to eliminate gear clashing and allow for smooth changing of gears. It also serves to lock these parts together.

3.The three stages of synchronization are: (1) The sleeve is moved toward the gear by the shifter lever. The movement of the sleeve causes the inserts to press the blocking ring into the cone of the gear. (2) The synchronizer sleeve slips over the teeth of the gear cone. This brings the gear to the same speed as the synchronizer assembly. (3) The sleeve slides over the gear teeth, locking the gear and its synchronizer assembly to the main shaft.

4.The front bearing retainer serves several functions: it houses on oil seal that prevents oil from leaking out the input shaft; it holds the front bearing rigid in the transmission case; and it serves as the sleeve for the throw-out bearing to ride on.

5.Reverse is obtained by the addition of an extra gear in the geartrain, called the reverse idler gear, which causes the reverse gear to rotate in a direction opposite the direction of the forward gears.

6.The transmission and transaxle are practically identical in operation; both provide torque multiplication and allow for synchronized shifting. Transaxles, however, contain the differential gears and are connected directly to the drive axles.

7.The major difference between the differential of a rear-wheel drive (RWD) vehicle and a front-wheel drive (FWD) vehicle is the way power flows. In RWD, power flow changes direction 90 degrees between the ring gear and the pinion. This change in direction is not needed with FWD because the transverse engine location places the crankshaft so that it is rotating in the correct direction.

8.The moving metal parts must not be allowed to touch and are separated by a thin film of lubricant. This film prevents friction and wear. Bearings also rely on lubricant to allow for smooth and low frictional rotation of gears and shafts.

9.When first gear is selected, the first and second gear synchronizer engages with first gear. This connects first gear with the output shaft. Since first gear and the input shaft are in constant mesh, power flows from the input shaft to the output shaft. This causes the output shaft to drive the differential ring gear.

10.Fifth gear in transmissions and transaxles reduces engine rpm at highway speeds, and therefore decreases fuel consumption and engine noise.

Fill-in-the-Blanks

1.Gears, power, drive wheels

2.Transmission, differential, drive axles

3.Hub, sleeve, blocker ring, inserts

4.Input gear

5.Shift forks

6.Main shaft

7.Sliding gear, collar shift, synchromesh

8.Constant mesh, collar shifted

9.Motor, automatic transmission

10.Gears, shaft

Multiple Choice

1.C

2.A

3.B

4.C

5.C

6.B

7.C

8.A

9.A

10.C

•Shop Manual, Pages 161–162

ASE-Style Review Questions

1.C

2.D

3.D

4.C

5.B

6.A

7.A

8.C

9.D

10.A

ASE Challenge

1.A

2.B

3.D

4.D

5.A