401dA Transmission Fundamentals - Part A Flashcards Preview

HET4 190401 Clutch/ Driveline/ Transmission > 401dA Transmission Fundamentals - Part A > Flashcards

Flashcards in 401dA Transmission Fundamentals - Part A Deck (20):
1

The function of a transmission is to only provide a means of increasing torque.
T/F

false; The transmission has three functions: to multiply the torque provided from the engine, to reverse the direction of torque delivery and to provide an interruption in torque while the clutch is still engaged.

2

The formula for determining gear ratio is the number of teeth on the driven gear divided by the number of teeth on drive gear.
T/F

true

3

The engine, transmission and other powertrain components must be carefully matched in order to achieve maximum service life in a specific vehicle and operating application.
T/F

true

4

An engine that develops high torque over several hundred rpm can be coupled with a transmission that has fewer gears (within reason).
T/F

true

5

Some vehicles carry loads over short distances at low speeds. Other vehicles pull loads over long distances at high speeds. An identical transmission, in terms of gearing and torque handling capacity, should be used in both applications.
T/F

false; Transmission gearing and torque handling capacities should be matched to each vehicle's normal operating application.

6

Explain two (2) functions of a synchronizer assembly.

- to match or synchronize the speed of a mainshaft gear with the speed of the mainshaft during the shifting process
- to temporarily connect a selected mainshaft gear to the mainshaft once the speeds of the mating parts have been synchronized

7

Identify three (3) types of commonly used synchronizer assemblies.

- blocktype synchronizers
- pin type synchronizers
- plate and disc synchronizers

8

Multiple countershaft transmissions only have two countershaft assemblies.
T/F

false; Some multiple countershaft transmissions have three countershaft assemblies.

9

Identify three (3) advantages of a multiple countershaft transmission.

- The countershafts,bearings and housings can be lighter because of the smaller forces they are required to withstand.
- Floating design eliminates the need for bearings between the mainshaft and the mainshaft gears.
- The gear width can be half as wide due to the doubled tooth contact area. As well, less expensive spur gears can be used, eliminating the need for thrust control washers.

10

When a multiple countershaft transmission is used, the main transmission section often has five (5) forward gear selections.
T/F

true

11

Multiple countershaft transmissions use several housings. These housings are kept in alignment through the use of:

precise dowelling.
(dowel pins)

12

The input shaft and gear:
a) deliver torque to the mainshaft gears.
b) are supported on bushings.
c) are driven by the clutch discs.
d) utilize a lip seal for sealing.

c) are driven by the clutch discs.

13

In a single countershaft constant mesh transmission, the countershaft gears:
a) are floating on the countershafts.
b) are in constant mesh with the mainshaft gears.
c) are identical from one countershaft to another.
d) are all individually replaceable.

b) are in constant mesh with the mainshaft gears.

14

The mainshaft gears are located in place on the mainshaft by:

a set of double washers.

15

What is used to reduce transmission noise from being transmitted up into the cab?

an isolator

16

The shift lever directly moves the __________________ in the shift bar housing.

shift rail

17

Identify the function of a detent system.

A detent system helps hold the shift rails in neutral or a selected position during operation.

18

Identify the function of an interlock system.

An interlock system prevents transmission damage by preventing two gears from being selected at once.

19

Identify the function of the spring-loaded plunger.

The spring loaded plunger prevents the operator from selecting first or reverse when the vehicle is moving forward at a great speed.

20

In an overdrive transmission, which of the forward gears would be direct?

fourth