Automatic Transmissions C27, C4 VehTech Flashcards
Full Study guide 2019
What is a flex plate used for?
To mount the torque converter to the crank shaft. Positioned between the engine crankshaft and the torque converter (Helps the distribution of heat)
Identify the three main parts of a torque converter.
Impeller/Pump, Turbine, and Stator
Which part of the torque converter rotates directly with the engine?
Impeller
What is the turbine directly connected to?
Coupled (Splined) to the transmission turbine shaft and forms the front half of the torque converter.
How does the fluid flow through the turbine?
Fluid from the impeller and the turbine vanes and flows around the split guide.
Where is the stator located?
Between the Impeller and the turbine, which is splinded to the outer race of a one way roller clutch mounted on the stator support.
List the lockup clutch components.
Backing plate, a lockup clutch plate, lockup clutch piston, splined to the converter.
Identify two types of lockup torque converters.
Centrifugal and piston
What does and overrunning clutch do?
Keeps the stator assembly from rotating when driven in one direction and permits overrunning (Rotation).
Which type of vehicle do piston type lock up clutches tend to be used?
Heavy Duty Truck Applications
What is the difference Between bushing and thrust washers?
Bushings are cylindrical shaped usually held in by press fit. (Radial Loads)
Thrust washers control free (axial movement), Inserted between various spots
What do bushings have to do with transmission fluid?
They are used to control fluid flow, some restrict flow, while others direct flow.
What do Thrust washers Control?
Used to help control heat expansion, used for proper end play.
What are Torrington bearings?
Thrust washers fitted with roller bearings, to limit end play and reduce friction between two moving parts.
What is the purpose of an overrunning clutch?
Used to hold and drive planetary gear sets
What are two types of overrunning clutches?
Roller type and One way Spring
In reference to multi-disc clutches list the components contained in the Drum?
Cylinder, Hub, Piston, Piston return springs, Seals, Pressure plate, Steel plate, Friction plate, and snap ring.
What does ATF do in the automatic transmission?
Extremely Important, Improves durability is used as a lubricant for the transmission to remove heat.
What does the pressure of ATF change?
Changes with Engine Speed, and Load
What are three types of oil pumps commonly used in automatic transmissions?
Gear, Vane, and Rotor Types
Pressure regulator valves are generally what type of valve?
Typically Spool valves, which toggle back and fourth
What does a kickdown circuit do?
Provides a downstep when the driver requires additional power. (Quick downshift)
Name the parts in a Planetary Gear Set?
Sun gear (Center Gear), Planetary Pinion gears, Placed inside a ring gear having internal teeth, and a Carrier
What are the laws of simple planetary gear operation?
Used to Increase or decrease torque and/or obtain neutral, low, Intermediate, high, or reverse.
What are the two types of oil flow in a torque converter?
Vortex and Rotary
Input, Output, Held =
Maximum Reduction
Held, Output, Input =
Minimum Reduction
Output, Input, Held =
Maximum Increase
Held, Input, Output =
Minimum Increase
Input, Held, Output =
Slow Reverse
Output, Held, Input =
Fast Reverse
When any two members are held together speed/direct the same?
Direct Drive
When no member is Held, results in?
Neutral
What is the purpose of venting in the automatic transmission?
Atmospheric pressure that forces fluid into a pump when the pump creates a low pressure in the inlet port.
List the parts of the Valve Body?
Valve Body, Separator plate, Transfer plate
How does a PRV work?
There is a valve and spring inside a PRV that you can set the pressure.
In a hydraulically Controlled Transmission what is the purpose of the governor?
The purpose is to either determine if the gear shifts up or down depending on the road speed.
What is the leading cause of Shift Delay?
For operating when there is a heavy load on the transmission the requires more torque then speed.
What is the purpose of a kick down?
Forces a quick down shift to allow for more power
List 7 components that provide input information to the TCM
MAP, TP, MAF, IAT, BARO, ECT, CKP
Most common planetary gear set?
Simpson
Identify all input circuit components
Shift selector, Throttle position sensor, Engine speed sensor, Turbine speed sensor, Output speed sensor, C3 pressure sensor, Sump Temperature sensor, Coolant sensor
What is the purpose of the VIM?
Housing that provides the necessary relays, fuses, and connection points.
How many types of solenoids are there in a WT Transmission and what are the called?
Two:
- Normally Open
- Normally Close
What are primary components of a hydraulic system?
Transmission fluid, Charging pump, Three integral filters, electro control modules, Breather, C3 Pressure switch.
How is a rotating clutch driven?
Splined to the turbine shaft, therefore rotates with turbine
What is the purpose of the balance piston?
A balance piston is used to enhance control of, off-going and On- coming rotating clutches.
How many gear options are available in the WT Transmissions?
Six total different options:
1,2,3,D,N,R
Which Clutches are engaged in first?
C1, C5
Which Clutches are engaged in Third?
C1, C3
Which Clutches are engaged in Fourth?
C1, C2
Which Clutches are engaged in Reverse?
C3, C5
