Going Old School….

Welcome back! Like the title suggests, this week we are going Old-School – looking at what entails a NON-computerized transmission. Yes…they do exist! But before we get into that, like always, time for a quick recap & review some definitions.

 

Previously on Anthony’s Automotive Blog….

 

Previously, we did a recap of the past few weeks – just to clear up any confusion any of you might have had. You can do a re-read of it here.

And prior to that (check it here), we discussed all the fun parts like Servo, Solenoid and just how the computerized transmission knows when to shift gears.

 

Our Growing Automotive Vocabulary

 

This week we added the following to our vocabulary: Governor, Vacuum, Modulator, Cable, Hinged, Spring, the combined specific terms of Vacuum Modulator and Throttle Cable as well as brought back a term we used awhile ago – Centrifugal. You can find them at the bottom of the list. As always, you can find our entire and current automotive dictionary here. Feel free to save its link so that you can find it again in case we use a word that happens to not be on this week’s list.

Here are the related words for this week’s topic. Enjoy expanding your vocabulary.

Automatic Transmission – An automotive transmission that can automatically change gears as the vehicle moves, freeing the driver from having to shift gears manually.

Hydraulic – Operated by the movement and force of liquid; specifically, operated by the pressure created when a liquid is forced through an aperture, tube, etc..

Valve – Any device in a pipe or tube that permits a flow in one direction only, or regulates the flow of whatever is in the pipe, by means of a flap, lid, plug, etc. acting to open or block passage.

Throttle – The valve that regulates the amount of fuel vapor entering an internal-combustion engine or controls the flow of steam in a steam line. This is also known as the Throttle Valve.

Governor – A mechanical device for automatically controlling the speed of an engine or motor as by regulating the intake of fuel, steam, etc..

Vacuum – An enclosed space, as that inside a vacuum tube, out of which most of the air or gas has been taken, as by pumping.

Modulator – Something that regulates, adjusts or adapts to the proper degree.

Cable – A thick, heavy rope, now often of wire strands.

Hinged – Jointed device on which a door, gate, lid, etc. swings.

Spring – A device, as a coil of wire, that returns to its original form after being forced out of shape: springs are used to absorb shock, and as the motive power in clocks and similar mechanisms.

Vacuum Modulator – A device that monitors the vacuum pressure in an engine and moves the throttle valve in a specific direction that is dependent upon the load of the engine.

Throttle Cable – A cable that is connected between the gas pedal and the throttle valve and monitors the position of the gas pedal.

Centrifugal – Moving or tending to move away from a center.

 

Look Ma – No Computers!

 

It’s hard to believe that there was a time when computers did not exist. They are wonderful and exasperating machines that make our lives both easier and more complicated. They are fantastic when they work properly and not so much when they don’t. And it’s also hard to believe that there was a time when there was not a single computerized part in our vehicles.

So exactly how did they work without computers? By simply using centrifugal forces, vacuums and cables.

 

                      The Governor “Arnold”

 

It all starts with the use of the Governor. Arnold here is attached to the output shaft and regulates the hydraulic pressure in the system based on the speed of the vehicle. It does this by spinning a pair of hinged weights against a pair of springs. The spinning causes a centrifugal force that pulls on the weights. As the weights get pulled out by the force, it pulls and stretches the springs. The further out the springs move, the more oil pressure is allowed to go past the Governor to then engage on the shift valves that are in the valve body. This would signal the engine on when to shift.

Also factored into this equation is the load that the engine is under. This is just simply how hard the engine is working. The higher the load on the engine, the longer the transmission will hold a gear before it will shift to the next one.

 

How to Lighten the Load

 

Non-Computerized monitoring of the load of the engine is done using one of two devices in conjunction with Arnold (aka the Governor). It is with either the Vacuum Modulator or the Throttle Cable.

                      1963 Corvette Modulator

 

The Vacuum Modulator is a device that is attached to the engine via a vacuum hose. When the engine is under a light load, a high vacuum is produced. Naturally, when an engine is under a heavy load, the vacuum pressure decreases down to non-existant. The other side of the Modulator is attached to the transmission, specifically the throttle valve in the valve body. Based on the vacuum level present, the modulator prompts the transmission to either shift early and softly or shift later and firmly.

Throttle Cable Attachment to the Transmission

 

The Throttle Cable just monitors the position of the gas pedal and prompts the throttle valve to shift based on its position.

 

For Next Week

And that’s a wrap on all things Automatic Transmission! You now know how this intricate piece of machinery works. Next Week, we’re going to discuss all the many things that can go wrong and we will give you some things to watch for in case your car needs a mechanic’s attention.

 

Until Next Time….

 Anthony’s Automotive

Your Automotive Vocabulary

In our replay from last week, I did not include any definitions for you. As we have gone on this journey, we have been adding words to your automotive vocabulary. You can always find the current list here.  But for ease of reading, here is the entire list in alphabetical order.

  • Automatic – A device or process that works by itself with little or no direct human control.
  • Automatic Transmission – An automotive transmission that can automatically change gears as the vehicle moves, freeing the driver from having to shift gears manually.
  • Band – Something that binds, ties together, restrains, etc.; a strip or ring of wood, metal, rubber, etc. fastened around something to bind or tie it together.
  • Centrifugal – Moving or tending to move away from a center.
  • Converter – A person or thing that causes a change in form, character or function.
  • Clutch – A mechanism for connecting and disconnecting a vehicle engine from its transmission system.
  • Driven Parts – The Wheels
  • Driveshaft – A rotating shaft that transmits torque in an engine.
  • Epicyclic – A circle whose center moves along the circumference of another, larger circle.
  • Flange – A projecting rim or collar on a wheel, pipe, rail, etc., to hold it in place, give it strength, guide it, or attach it to something else.
  • Gasket – A shaped piece or ring of rubber or other material sealing the junction between two surfaces in an engine or other device.
  • Gear – One of a set of toothed wheels that work together to alter the relation between the speed of a driving mechanism (such as the engine of a vehicle or the crank of a bicycle) and the speed of the driven parts (the wheels).
  • Hydraulic – Operated by the movement and force of liquid; specifically, operated by the pressure created when a liquid is forced through an aperture, tube, etc..
  • Input – The act of putting in; or, what is put in.
  • Manual – A thing operated or done by hand rather than automatically or electronically, in particular.
  • Manual Transmission – An automotive transmission consisting of a system of interlocking gear wheels and a lever that enables the driver to shift gears manually.
  • Neutral – A disengaged position of gears in which the engine is disconnected from the driven parts.
  • Oil – Any of various kinds of greasy, combustible substances obtained from animal, vegetable, and mineral sources; oils are liquid at ordinary temperatures and soluble in certain organic solvents, as ether, but not in water.
  • Output – The work done or amount produced by a person, machine, production line, manufacturing plant, etc., especially over a given period.
  • Pack – A number of similar or related persons or things.
  • Pipe – A long tube of clay, concrete, metal, wood, etc., for conveying water, gas, oil, etc. or for use in construction. Also, anything tubular in form.
  • Piston – A disk or short cylinder closely fitted in a hollow cylinder and moved back and forth by the pressure of a fluid so as to transmit reciprocating motion to the piston rod attached to it, or moved by the rod so as to exert pressure on the fluid.
  • Planetary Gear System – A gear system that consists of one or more planet gears (the gears in the middle area) that rotate or revolve around a sun gear (the gear in the center) and a ring gear (the gear on the outer edge).
  • Pump – Any of the various machines that force a liquid or gas into or through, or draw it out of, something, as by suction or pressure.
  • Radiator – A device of tubes and fins, as in an automobile, through which circulating water passes to radiate superfluous heat and thus cool the engine.
  • Regulator – A mechanism for controlling or governing the movement of machinery, the flow of liquids, gases, electricity, steam, etc..
  • Seal – A device or substance that is used to join two things together to prevent them from coming apart or to prevent anything from passing between them.
  • Servo – This is short for Servomechanism OR Servomotor.
  • Servomechanism – An automatic control system in which the output is constantly or intermittently compared with the input through feedback so that the error or difference between the two quantities can be used to bring about the desired amount of control.
  • Servomotor – A device, as an electric motor, hydraulic piston, etc., that is controlled by an amplified signal from a command device of low power, as in a servomechanism.
  • Shaft – A long, slender part or object.
  • Solenoid – A coil of wire, usually wound in the form of a helix, that acts like a bar magnet when carrying a current: used in brakes, switches, relays, etc..
  • Soluble – That can be dissolved; able to pass into solution.
  • Solvent – A substance, usually liquid, that dissolves or can dissolve another substance.
  • Spline – A flat key or strip that fits into a groove or slot between parts.
  • Sprag – A device for preventing a vehicle from rolling backward on a grade.
  • Stator – A fixed part forming the pivot or housing for a revolving part, as in a motor, dynamo, etc..
  • Throttle – The valve that regulates the amount of fuel vapor entering an internal-combustion engine or controls the flow of steam in a steam line. This is also known as the Throttle Valve.
  • Torque – A twisting force that tends to cause rotation.
  • Torque Converter – A device that transmits or multiplies torque generated by an engine.
  • Transmission – The mechanism by which power is transmitted from an engine to the wheels of a motor vehicle.
  • Tube – A hollow cylinder or pipe of metal, glass, rubber, etc., usually long in proportion to its diameter, used for conveying fluids, etc..
  • Turbine – An engine or motor driven by the pressure of steam, water, air, etc. against the curved vanes of a wheel or set of wheels fastened to a driving shaft.
  • Valve – Any device in a pipe or tube that permits a flow in one direction only, or regulates the flow of whatever is in the pipe, by means of a flap, lid, plug, etc. acting to open or block passage.

 

Thoughts for Next Week

Next week we will dive back into the transmission and take a look at the difference between what goes on with a non-computerized transmission. You will be surprised at the difference.

 

Until Next Time….

Anthony’s Automotive

One, Two, Three…Replay!

Welcome back! I know last time we said that we’d look at how the non-computerized transmissions work but we’re going to hold off on that. Instead, let’s review all that we have learned over the past several weeks. We want to make sure you have a good understanding of how the transmission works before we add any new data and concepts to this.

 

The Automatic Transmission

 

In this photo, you will see exactly what we’ve been talking about for the past several weeks. This is the side view of your car’s transmission. You can even see the Gear Shift attached. This photo gives a great perspective on how the transmission looks and where everything is placed in relation to each other.

Transmission with Gear Shift

Side view of transmission with the attached Gear Shift

Now…how does it work again?

You put your key in the ignition and you turn your car on. The engine is now running and the Torque Converter has been engaged. Transmission fluid is now pumping through your car’s transmission via the Pump, through the Turbine, into the Stator and into the One Way Clutch. This essentially keeps your engine running and keeps your car moving while its shifting gears, idling, etc..

When you shifted your Gear Shift into the Drive position, you have basically put it into First Gear and told your car that you want all the gears available for it to use while you are moving forward.

Now back to the One Way Clutch – the transmission fluid doesn’t just stop there. It keeps moving. Through a complex series of passages and tubes, the fluid moves into the Valve Body of your car’s transmission. And it does this only because it is under pressure the entire time.

This pressure is generated by the Oil Pump when you turn your engine on. It is connected to the torque converter which means it is connected to both the engine and the transmission. As long as there is sufficient oil located in the oil pan (on the bottom side of the transmission), it will create pressure and will allow the transmission fluid to flow through the transmission.

Now back to the Valve Body – transmission fluid is directed to the channels that lead to specific valves required to allow a gear shift to occur.

 

And how exactly does it know which channels to use?

 

In a computer controlled transmission, there are sensors that are used to capture lots of data related to your engine: brake pedal position, engine load (how ‘hard’ it’s working), engine speed, vehicle speed and many more. By compiling all this information, it can exactly pinpoint when a gear shift needs to occur. AND when it has properly identified that moment, it transmits to the Solenoid Packs in the transmission so that they can redirect the transmission fluid as needed to the correct clutch pack/band/servo to shift the gear.

Remember – a Solenoid Pack is simply a coiled wire that acts like a magnet when an electrical current is running through it and it can easily open and close valves.

 

In a Nutshell

You turn your car on. This causes the oil to create pressure that allows the transmission fluid to flow through the valve body, which selects the optimum gear for your car to be in at that specific moment. All you do is turn the car on, tell your car you want ALL the gears (putting in Drive) and put your foot on the gas pedal.

 

 

Until Next Time….

 Anthony’s Automotive

One Valve, Two Valve, Three Valve, Four….

Welcome back! This week we are going to see what exactly the Valve Body is and the purpose it plays in your automatic transmission. But before we get into that, like always, time for a quick recap & review some definitions.

Previously on Anthony’s Automotive Blog….

Last week, we drilled a well and learned all about Texas Tea and just how important Oil is to your car’s transmission. You can do a re-read of it here. Or, keep reading for the quick recap.

Oil and the pump it goes through creates the pressure necessary for your transmission to function…period. It is this pressure that keeps the transmission fluid flowing throughout your car’s system, which, in turn, keeps it cool, changes gears and lubricates just about everything else and keeps parts moving. Let’s face it – we like moving parts.

We’ve added a few words this week: Pipe, Valve, Servo, Servomechanism, Servomotor, Solenoid, and Throttle. You can find them at the bottom of the list. As always, you can find our entire and current automotive dictionary here. Feel free to save its link so that you can find it again in case we use a word that happens to not be on this week’s list.

Our Growing Automotive Vocabulary

Here are the related words for this week’s topic. Enjoy expanding your vocabulary.

Transmission – The mechanism by which power is transmitted from an engine to the wheels of a motor vehicle.

Automatic – A device or process that works by itself with little or no direct human control.

Automatic Transmission – An automotive transmission that can automatically change gears as the vehicle moves, freeing the driver from having to shift gears manually.

Clutch – A mechanism for connecting and disconnecting a vehicle engine from its transmission system.

Band – Something that binds, ties together, restrains, etc.; a strip or ring of wood, metal, rubber, etc. fastened around something to bind or tie it together.

Pump – Any of the various machines that force a liquid or gas into or through, or draw it out of, something, as by suction or pressure.

Hydraulic – Operated by the movement and force of liquid; specifically, operated by the pressure created when a liquid is forced through an aperture, tube, etc..

Oil – Any of various kinds of greasy, combustible substances obtained from animal, vegetable, and mineral sources; oils are liquid at ordinary temperatures and soluble in certain organic solvents, as ether, but not in water.

Pipe – A long tube of clay, concrete, metal, wood, etc., for conveying water, gas, oil, etc. or for use in construction. Also, anything tubular in form.

Valve – Any device in a pipe or tube that permits a flow in one direction only, or regulates the flow of whatever is in the pipe, by means of a flap, lid, plug, etc. acting to open or block passage.

Servo – This is short for Servomechanism OR Servomotor.

Servomechanism – An automatic control system in which the output is constantly or intermittently compared with the input through feedback so that the error or difference between the two quantities can be used to bring about the desired amount of control.

Servomotor – A device, as an electric motor, hydraulic piston, etc., that is controlled by an amplified signal from a command device of low power, as in a servomechanism.

Solenoid – A coil of wire, usually wound in the form of a helix, that acts like a bar magnet when carrying a current: used in brakes, switches, relays, etc..

Throttle – The valve that regulates the amount of fuel vapor entering an internal-combustion engine or controls the flow of steam in a steam line. This is also known as the Throttle Valve.

Come in Houston! Do you read me??

Last week we talked about how the transmission fluid is the ‘blood’ that flows through your car. And, that it is the oil that creates the ‘blood pressure’ of the system. Using this same type of analogy, the Valve Body is the ‘brain’ of your vehicle. This is where everything is controlled. We touched briefly on the Valve Body and its purpose a while ago here.

 

A Valve Body

A Valve Body

 

In a nutshell, the whole purpose of the Valve Body is to smoothly shift gears as you are driving down the road. That is all. The Valve Body is an intricate & specialized maze of channels that directs the transmission fluid that activate whatever gears are needed to shift to.

For example, if the car needs to shift from second to third gear, the transmission fluid needs to flow through the channels to the specific valve that is for that function. This valve is often called the 2-3 valve. And oddly enough, there is a specific valve for shifting from third back to second and it’s commonly called the 3-2 valve. In this system, there is a valve for everything!

 

Simple Gear Shift Stick

Simple Gear Shift Stick

 

The most important valve is the Manual Valve. THIS is the valve that you actually have direct control over and basically gets the whole process going. The Manual Valve is the one that is directly connected to your gear shift. In an automatic transmission, the second you move the gear shift into the Drive position, the Manual Valve directs the transmission fluid to the clutch packs that activate 1st Gear. At the same time, it engages the monitoring of your vehicle’s speed and throttle position to best determine the correct time and force needed to do the shift from 1st Gear into 2nd Gear.

Most automatic transmissions nowadays are computer controlled with electrical solenoids mounted in the Valve Body to help with the direction of fluid to the appropriate clutch packs, bands or servos. This is done to make your car more efficient and to be more precise in determining shift points while you are moving.

My Sole….what??

It’s a Solenoid Pack. To further simplify the definition we listed above – It is simply a coiled wire that acts like a magnet when an electrical current is running through it. By acting like a magnet, it can easily open and close valves.

Now, in a computer controlled transmission, there are sensors that are used to capture lots of data related to your engine: brake pedal position, engine load (how ‘hard’ its working), engine speed, vehicle speed and many more. By compiling all of this information, it can exactly pinpoint when a gear shift needs to occur. AND when it has properly identified that moment, it transmits to the Solenoid Packs in the transmission so that they can redirect the transmission fluid as needed to the correct clutch pack/band/servo to shift the gear.

For Next Week

This week we’ve touched on how a computer controlled transmission works by interacting with sensors and solenoid packs. Next week, let’s go old school and take a look at how non-computerized transmissions work and what parts they have that differ from the computerized ones.

Until Next Time….

 Anthony’s Automotive