Transmission Fundamentals Flashcards

1
Q

what are the three functions of a transmission

A

. to multiply torque from the engine through a series of gear options
. to provide a means of reversing the direction of torque delivery from the engine
. to provide an interruption in torque ( neutral ) while the clutch is still engaged

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

transmission classifications

A
. synchronized or non-synchronized 
. single or multiple countershaft 
. number of forward  gear ratio 
. manual or automatic
. final gear ratio ( direct or overdrive )
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

how do you calculate output torque on a transmission

A

input torque must be multiplied by the final gear ratio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

how do you calculate output speed on a transmission

A

input speed must be divided by the final gear ratio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are the main components in a heavy duty transmission

A
. Transmission input shaft and drive gear 
. Mainshaft and mainshaft gears 
. Synchronizers 
. a shift lever 
. shift rails and forks 
. detents 
. interlocks
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the initial component to receive power from the engine

A

transmission input shaft also called the clutch shaft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what happens when the clutch is engaged

A

it is trapped between the flywheel and the pressure plate friction surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is the purpose of the tapered roller bearing located in the casting ahead of the input shaft gear

A

to center the shaft in the front of the transmission case and provides a means of adjusting mainshaft endplay

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how is the input shaft bearing retainer cover adjusted to have the proper endplay on the bearing cup and cone

A

shims

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is the mainshaft and gear assembly is different from the countershaft how ?

A

the main shaft is a sperate shaft that operates independently of the main shaft gears

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how are the helical gears on a mainshaft held in place

A

with thrust washers, snap rings and lock pins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

why are more thrust washers needed on a mainshaft than a countershaft

A

because the gears are not connected to the mainshaft so each individual gear requires thrust washers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the tang on a thrust washer used for

A

as a locating device

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is a synchronizer

A

a type of clutch or brake that is used to match the speed of the mainshaft with a mainshaft gear during the shifting process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are the three types of synchronizers

A

block type
plate and disc type
pin type

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is used to transmit the actions of the operator to the shift fork and rails

A

the shift lever

17
Q

what is used to reduce transmission noise up into the cab in a shift lever assembly

A

an isolator

18
Q

what is the purpose if the shift rails and fork

A

to take the operators input from the gear shift lever and move the sliding clutches to engage the desired mainshaft gear

19
Q

what allows proper gear selection without clashing gears

A

by only allowing one sliding clutch to be moved at one time

20
Q

what is the purpose of the detents in a heavy duty transmission

A

to hold a shift rail in the selected position whether in a neutral or engaged position

21
Q

how many recesses are there in a shift rail

A

there are usually three recesses in each shift rail

22
Q

why must the operator overcome a definite amount of force to shift into first or reverse

A

to prevent accidental shifting during operation

23
Q

in order to prevent the operator from selecting more than one gear at a time

A

interlocks

24
Q

what are some advantages of multiple countershaft transmissions

A

. smaller and lighter countershafts, Bearings and housings
. Floating design of mainshaft gear
. Narrower gear teeth width required

25
what type of synchronizer is a multi piece unit composed of a central hub, two soft metal blocker rings, a shift collar. a set of inserts and two insert springs
block type synchronizer
26
what is the first reduction device used to increase the available engine torque
the transmission
27
how is torque divided in a twin countershaft design
it is split evenly between both countershafts 180 degrees apart
28
how is torque divided in a triple countershaft design
between all three countershafts 120 degrees apart
29
what are some advantages of multiple countershaft transmissions
. smaller and lighter countershafts, bearings and housings . floating design of mainshaft gear . Narrower gear teeth width required
30
how many reverse idler gears are needed in a multi countershaft design
one for each countershaft
31
the mainshaft gears are located in place by
a set of double washers
32
the shift lever directly moves what in the shift bar housing
shift rail
33
multiple countershaft transmissions use several housings , these housings are kept in alignment through the use of .
precise dowelling