190303b torque converter fundamentals and service

Question 1

What are the three V’s pertaining to hydrodynamic drives?

Answer 1

Volume of oil, velocity of oil, Viscosity of oil used

Question 2

What drives the torque converters Impeller? and what does it do?

Answer 2

The engine, it “throws oil” at the turbine to turn mechanical energy to hydraulic energy

Question 3

What is the purpose of the turbine?

Answer 3

It is the output element which transmits torque to a driveline or transmission: it receives hydraulic energy from the impeller and converts it to mechanical energy

Question 4

When condition is the torque converter most useful?

Answer 4

At stall, it creates the highest torque multiplication

Question 5

What 3 things are an advantage to FLUID COUPLERS? and what the the disadvantages of a FLUID COUPLER?

Answer 5

advantages: no mechanical connection, shock absorption, gradual start up of load.
Disadvantages: efficiency is lost due to slippage, cannot have a true 1:1 ratio, creates heat

Question 6

What component adds torque multiplication to a fluid coupler?

Answer 6

a stator

Question 7

Name the two types of flow through a torque converter or fluid coupler? explain the flow?

Answer 7

Rotary flow: when the turbine and impeller are at the same speed (nearly) and it is in its “coupling phase”, oil flow is turning the same direction as the two coupled units
vortex flow: when the turbine is not moving and a “corkscrew” oil flow through the converter (or coupler) is creating its highest torque also called its “converter phase”

Question 8

What does a split guide ring do?

Answer 8

Prevents turbulence within a converter while it is in operation (smooths flow of oil)

Question 9

What does a stator actually due to create torque?

Answer 9

changes direction of oil flow

Question 10

What effect do the angle of the blades have on torque multiplication?

Answer 10

it can change the amount of torque multiplication based on what the manufacture design is.

Question 11

When is the most torque created in a converter? and what happens as speed increases?

Answer 11

At stall, as speed increases less torque is created

Question 12

What are the two types of stator? and what effect would they have on torque and the amount of “phases” a converter can do?

Answer 12

A fixed stator, which creates only torque (single phase converter) so no true coupling phase could happen, a freewheeling stator (2 phase) allows both torque multiplication and a coupling phase

Question 13

What are the 3 “phases” of a converter? and what is the flow through the converter?

Answer 13

converter phase (vortex flow), coupling phase (rotary flow) and lock up phase (mechanically locked with a clutch)

Question 14

does a converter create a full 1:1 ratio?

Answer 14

no, unless coupled with a mechanical clutch

Question 15

What positions create what with a freewheeling stator? in regardless to flow?

Answer 15

rotary flow : stator turning with impeller and turbine, vortex flow : stator stationary

Question 16

What kind of variable capacity converters are there?

Answer 16

multiple impeller, multiple turbine, variable pitch stator

Question 17

What components are required when using a multiple impeller variable capacity converter?

Answer 17

a piston and clutch to lock one impeller to the other

Question 18

What component is required when using a multiple turbine type variable capacity converter? Explain its positions based on speed

Answer 18

an overrunning clutch, in slower speeds the clutch locks up and allows higher torque generation, when the impeller speeds up it allows the overrunning clutch to freewheel because it is now turning faster

Question 19

What controls the vanes on a variable pitch stator? and what position of the vanes creates maximum torque?

Answer 19

a hydraulically operated bellcrank, open position does, closed creates the highest speed

Question 20

What does the torque converter inlet relief do?

Answer 20

protects the converter during cold start ups, plugged filter or restriction in the system

Question 21

What does the torque converter outlet relief do?

Answer 21

maintains the working pressure inside the converter, prevents cavitation and aeration, and helps keep oil in the converter

Question 22

What defines an element in regards to torque converters?

Answer 22

A set of blades

Question 23

What is a stage defined as?

Answer 23

The amount of times the oil strikes the turbine before it returns to the impeller

Question 24

during a catastrophic converter failure what could potentially happen to the transmission lubrication circuit or inlet of the hydraulic system (in regards to a torque converter setup)

Answer 24

the oil cooler can potentially plug up with debris and not allow oil to the transmission lubrication circuit which can create issues with the transmission (lack of lubrication to shafts, gears and clutches)

Question 25

What temperature is considered unsafe for transmission oil?

Answer 25

above 121 degrees celsius, or 250 degrees fahrenheit

Question 26

what defines a dry type converter housing?

Answer 26

a dry housing does not have any pto drive gears or other forms of gearing, the converter is sealed.

Question 27

What defines a wet type housing?

Answer 27

a wet type housing has drive gears that drive a pto, and are required to be lubricated, the converter itself may still be enclosed and not allowed to leak, but the housing surrounding it is “wet”

Question 28

What is required for a wet housing? explain?

Answer 28

removal of lubrication oil from lubricating bearings on the pto drive gears, either from gravity drain, or a scavenge pump, or drag will affect torque converter operation, and it could potentially overheat

Question 29

what kind of pump is a scavenge type pump?

Answer 29

a non-positive displacement pump, which produces no pressure, just sucks and removes oil back to sump

Question 30

how much wood could a wood chuck chuck, if a wood chuck could chuck wood?

Answer 30

I have no friggen idea

Question 31

what is a torque divider?

Answer 31

its a torque converter with a planetary gear set attached to it

Question 32

What planetary gears are attached to which component of the converter?

Answer 32

Sun gear and impeller are attached together, the internal gear and turbine are attached together and the carrier is attached to the output shafts, stator is fixed to the housing

Question 33

engine idling output shaft stalled causes what to happen to the planetary gears or a torque divider?

Answer 33

sun gear and impeller rotating normally, internal gear and turbine rotating in reverse, as there is no load on the output shaft, carrier is held (output shaft)

Question 34

What causes machine to start moving?

Answer 34

resistance on the output shaft creates a resistance and allows the machine to start moving (rpm drop)

Question 35

What happens when engine speed increases and the output shaft is still stalled on a torque divider?

Answer 35

reverse direction of the turbine starts creating maximum flow,

Question 36

what is a phase?

Answer 36

a functional change

Question 37

What creates a high stall speed?

Answer 37

slipping forward clutch, problem in the torque converter, internal leakage or cavitation or worn out seals, overfueling

Question 38

What creates a low stall speed?

Answer 38

not producing proper torque, due to a slipping stator over running clutch (possibly backwards) plugged air filter

Question 39

what can cause overheating?

Answer 39

operator error, over stalling, no downshifts plugged oil cooler (internal or external) radiator fan failure,

Question 40

What is important when it comes to installing a new torque converter?

Answer 40

pre-lubrication as it may take a bit for lubrication to get to bearings right away

Question 41

where are the two places you can mount a converter?

Answer 41

engine mount (integral) or remote (external)

Question 42

why is crankshaft endplay important?

Answer 42

serious damage can occur is something isn’t right (shim on wrong side of bearing etc)

Question 43

why shouldn’t you clean aluminum in a hot tank?

Answer 43

the chemical can eat away at the aluminum and destroy the soft material

Question 44

What is a stationary reactor

Answer 44

A stator could be considered this, something that doesn’t move, and reacts to the forces acting upon it.