Manual Transmissions

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Manual Transmissions
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• Sliding Gear Transmission
• Old school, used from late 1800s to 1940s?
• Has two or more shafts in parallel with sliding
  spur gears.

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• Sliding Gear Transmission
• If either gear is rotating, shifting is difficult
  and gear clashing will result.
• Some manufacturers may still have a sliding gear
  for reverse.

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• Collar-shift Transmission
• Has two parallel shafts with gears in constant
  mesh
• These collars slide on a hub that is splined to
  the output shaft, thus transferring power.
• Gear clashing will occur if the gear speeds are
  not matched by double clutching.

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Double Clutching

• The shifter, rather than going straight to the
  next gear, makes a stop in neutral and then the
  clutch is released.
• This is to allow the engine to slow down (or with
  a tap on the gas, speed up when downshifting) so
  the transition into the next gear is much more
  smooth.
• The driver then depresses the clutch again and
  completes the shift into the target gear, and
  finally the clutch is released again, putting the
  car back into gear.

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Synchromesh Transmissions
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Synchromesh Transmissions

• Gears are in constant mesh and are collar shifted
• All forward gears are of a helical design

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Synchromesh Transmissions

• Collars are equipped with synchronizers
• Synchronizers eliminate the need to equalize gear
  speeds before engagement
• Used on all current models of cars may use a
  spur gear for reverse

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Synchromesh Transmissions

• Engine torque is applied to the input shaft
  (clutch shaft) when the clutch is engaged.
• The input shaft is fitted with a gear (input gear
  or clutch gear)
• The output shaft (main shaft) is inserted into,
  but rotates independently of the input shaft.

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Synchromesh Transmissions
The different speed gears (1st, 2nd, 3rd 4th,
etc.) rotate on the main shaft.
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Synchromesh Transmissions

• Parallel to (below or beside) the input and
  output main shaft is the counter shaft
• The counter shaft is fitted with different sized
  gears.

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Synchromesh Transmissions

• All of these gears are in constant mesh with the
  gears on the output shaft except

• One gear is in constant mesh with the input shaft
  gear.

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Synchromesh Transmissions

• Gear changes occur when the selected gear is
  connected to the output shaft.
• This is accomplished by locking a collar onto the
  selected gear.
• The collars are moved by shift forks.

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Synchromesh Transmission
Switch to ppt 2
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Transmission Components
Input Shaft
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Main (Output) Shaft
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Counter Shaft
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Synchronizer Assembly
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Synchronizer Operation
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Synchronizer Operation

• First, the sleeve is moved toward the gear by the
  shift lever and engages the hub assembly
• Second, the movement of the sleeve causes the
  inserts to press the blocking ring onto the
  cone of the gear

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Synchronizer Operation

• Third, when the components reach the same speed,
  the synchronizer sleeve slides over external dog
  teeth on the blocking ring and over the dog teeth
  of the speed gears shoulder. This action locks
  the gear to the main shaft.

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Fork and Rail Assembly
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Reverse Idler Gear
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Transmission Operation

• Power flow in neutral
• The input shaft drives the counter shaft
• All of the gears on main shaft rotate
• The synchronizers are not engaged with any gear
• No power is transferred to the output shaft

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Power flow in first gear

• The power enters the transmission through the
  input shaft
• The first/second synchronizer sleeve is engaged
  with the first gear dog teeth
• The power is transferred from the input shaft,
  through the countershaft, and up to the first
  gear
• The first gear drives the output shaft

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Power flow in second gear

• The power enters the transmission through the
  input shaft
• The first/second synchronizer sleeve is engaged
  with the second gear dog teeth
• The power is transferred from the input shaft,
  through the countershaft, and up to the second
  gear
• The second gear drives the output shaft

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Power flow in third gear

• The power enters the transmission through the
  input shaft
• The third/fourth synchronizer sleeve is engaged
  with the third gear dog teeth
• The power is transferred from the input shaft,
  through the countershaft, and up to the third
  gear
• The third gear drives the output shaft

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Power flow in fourth gear

• The power enters the transmission through the
  input shaft
• The third/fourth synchronizer sleeve is engaged
  with the fourth gear dog teeth
• The power is transferred from the input shaft to
  the fourth gear
• The fourth gear drives the output shaft

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Power flow in fifth gear

• The power enters the transmission through the
  input shaft
• The fifth gear synchronizer sleeve is engaged
  with the fifth gear dog teeth
• The power is transferred from the input shaft,
  through the countershaft, and up to the fifth
  gear
• The fifth gear drives the output shaft in
  overdrive

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Power flow in reverse gear
Reverse is often achieved by adding a third gear
-causing the output shaft to spin in the
opposite (same) direction
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Power flow in reverse gear

• The power enters the transmission through the
  input shaft
• The reverse gear synchronizer sleeve is engaged
  with the reverse gear dog teeth
• The power is transferred from the input shaft,
  through the countershaft, through the reverse
  idler gear, and up to the reverse gear
• The reverse gear drives the output shaft in
  reverse

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GEAR RATIO
FINAL

• 1st 2.661
  9.101
• 2nd 1.781
  6.101
• 3rd 1.301
  4.451
• 4th 1.001
  3.421
• 5th 0.741
  2.531

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Transaxle
A manual trans-axle is almost identical to a
manual transmission except 1. The differential
is built into the housing 2. The input shaft
incorporates gears 1,2,3 _at_4 2. The counter-shaft
is now the output shaft 3. The gears are
generally smaller and pressed fit to facilitate a
smaller area.
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Transaxle
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Transaxle
Input and output shafts
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Transaxle
First Gear
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Transaxle
Fourth Gear
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Transaxle
Reverse
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Transaxle Final Drive
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Shifter Rails
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Interlock System
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Fork and Rail Assembly (internal)
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Fluids
are used to _ ? _ ? check the manufacturers
specifications!