unit 4 Flashcards
An electronic solenoid used to prevent accidental engagement into reverse gear while the vehicle is moving forward.
electronic reverse lockout
A part of the synchronizer that helps hold the synchronizer collar in position.
spring-loaded key
A shift fork used to engage the reverse gear.
reverse shift fork
The use of a small gear to drive a large gear. The result is in an increase in torque but a decrease in speed.
gear reduction
A synchronizer used in all current transmissions. It uses a blocking ring. Also called a blocker ring synchromesh unit.
baulk-ring synchromesh unit
The curve created by a smooth spiral and used in the angle of gear teeth and coil springs.
helix
A seal that has a spring to maintain pressure on the seal’s surface to prevent leakage.
garter spring lip seal
A mechanism that moves the synchronizer sleeve to lock the gear to the main shaft.
shift fork
The increase of torque.
torque multiplication
Resistance that is present from tires contacting the road and wind resistance against the vehicle while rolling down the highway.
rolling resistance
The U-shaped cutaway in shift shafts that the shifter lever fits into.
selector gate
A shifting problem in which the shifter will not move smoothly into the desired gear, requiring excessive force by the driver to set it into gear.
hard shifting
A rounded or angled edge located on the blocking ring, with ridges machined into it to help grab the cone surface of the gear.
chamfer
A gear used in between two gears to change the direction of the rotation of the driveshaft or drive axles in the transmission.
idle gear
A mechanical device that prevents engagement of two different gears at the same time
interlock mechanism
The sleeve that slides to lock the selected gear to the main shaft. The synchronizer sleeve is part of the synchronizer assembly.
synchronizer sleeve
An electronic sensor that reads the driveshaft speed and sends either an analog or a digital signal to the computer that corresponds to the road speed of the vehicle.
vehicle speed sensor
The cam and lock pin operated by an electronic solenoid that keeps the reverse gear in lockout until it is selected.
lockout solenoid
A shifting mechanism or electronic control usually attached to the steering wheel.
paddle
Oil seal flutes or swirls that are part of the oil seal and that create a pumping action to return oil to the transmission as the shaft rotates, enabling lubrication.
hydrodynamic seal
A rod that is attached to the shift fork. These rails move when the shifter lever is moved against them.
selector shift rail
A seal that is a complete circle. If a cutaway is done, it will also be a complete circle. These seals are usually set into a groove that is machined into the housing or part that does not move and is intended to be sealed.
o-ring seal
A roller in the rear of the input shaft that supports the front of the main shaft.
pocket bearing
An assembly that allows for the selection of gears without grinding by matching the speed of the two assemblies.
synchronizer
A long cylindrical roller held in position by a cage.
roller bearing
The lever that the driver uses to shift the transmission.
gear shift lever
The mechanism that holds or helps hold the shift rail into position to ensure that the gear does not pop out when selected and to let the driver feel when a shift is completed.
detent mechanism
A hydraulically controlled cylinder that engages or disengages the clutch pedal.
hydraulic actuator
Resistance encountered when a vehicle travels up a hill, requiring torque to be applied to overcome it.
gradient resistance
A shim of a prescribed thickness that is used to control shaft clearances in a transmission.
selective thickness shim
A technique used to shift gears when a non-synchronized transmission is used. The driver must push the clutch in multiple times to change gears.
double clutching
Typically a small-diameter pin rolling bearing that can be held in a cage or placed into the inside diameter of a hole.
needle roller bearing
A synchronizer part that increases or decreases a gear’s speed to match shaft speed so that the synchronizer sleeve can lock the gear to the shaft. Also called baulk ring.
blocking ring
A condition in which the engine and transmission output are turning at the same rate of speed.
direct drive
