Manual Transmissions & Transaxles Flashcards
What is the purpose of the transmission?
Multiply engine torque, Lower engine RPM (O/D) and allow change in direction (R)
What is gear pitch?
the number of teeth per given unit of pitch diameter
What is pitch diameter?
distance from the halfway point of 2 furthest apart gear teeth
What is Pitch Circle?
the halfway point of the gear teeth
Where is the Face on a gear?
above the pitch circle (tooth center line)
Where is the Flank on a gear?
below the pitch circle (tooth center line)
What is direct drive?
same size gears
What is underdrive?
a larger drive gear (more torque)
What is overdrive?
a smaller drive gear (more speed)
list the parts and describe the ‘exploded view’ of a synchronizer
A center hub surrounded by 3 [inserts/shifting keys]. These are held together by a [sleeve] and secured with [lock rings/key springs] on either side. This whole assembly is sandwiched between 2 [blocking inserts] making up the entire [Synchronizer]
Describe the flow of power on a Transmission
Power flow enters from the [Input shaft] and then is transferred through the [Clutch gear] to a lower [Countershaft]. Then through the selected [Speed gear] and back up to exit out the [Output shaft].
Only exception is 4th gear where its transferred directly from the [Input shaft] to the [Output Shaft]
Describe the flow of power on a Transaxle
Power flow enters from the [Primary Shaft] and then is transferred through selected [Speed Gear] down to the [Secondary Shaft] and out the [Ring Gear]
What does the shifting interlock feature do?
Prevents engaging 2 gears at once
What do the detents balls and springs do?
Prevents gear from ‘popping out’
What benefit does a Transaxle have over a Transmission?
Its more compact and eliminates the need for high speed drivelines
How do you measure an shaft bearing journals?
Outside Micrometer
How do you measure inner race flange thickness’?
Caliper
How do you measure shaft runout?
Rotate on V-blocks and measure with Dial Indicator
How do you measure clearance between Shift fork and shift sleeve?
Feeler Gauge
What is the formula for finding gear ratios?
Driven / Driver
How does a Dual-Clutch Transmission work?
Operates as 2 separate manual transmissions working in parallel
What benefits does a Dual-Clutch Transmission have?
a DCT can shift gears faster and is more efficient, durable and lighter
How many forward speeds can a DCT have?
6-7
What is the difference between a Wet and Dry Dual-Clutch?
Dry clutches are smaller, lighter, cheaper and produce less power, therefor more common in FWD vehicles
Wet clutch is more powerful and housed in a drum completely submerged in oil
