All about the Valves

Welcome back! This week we’re still on the topic of Transmissions. But this time, let’s get a little more technical know-how under your belts. But before we jump right in, let’s do a quick recap & review some definitions.

 

Previously on Anthony’s Automotive Blog….

 

Last week, we talked about just the basics when it comes to transmissions. If you wish to do a quick re-read of it, you can find it here. For a quick recap, keep reading.

Basically, your car’s transmission is what keeps it moving. They come in two flavors: Automatic or Manual (aka Stick Shift). Automatic transmissions require little to no interaction from the driver, while Manual transmissions require 100% interaction from the driver. Your transmission needs a special fluid to keep all of its parts working together. We also touched on some common problems that can occur & how to tell if it’s about to die.

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We also covered some basic definitions of various automotive-speak words that you could understand exactly what it was that I was saying. Let me recap a couple of those words here just in case. I will also add some new ones, as they do pertain to this week’s particular topic.

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

Torque Converter – A device that transmits or multiplies torque generated by an engine.

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).

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.

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.

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

Epicyclic – A circle whose center moves along the circumference of another, larger circle.

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).

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..

 

The Nuts and Bolts of an Automatic Transmission

 

As you recall, an automatic transmission is the type of transmission that requires little to no interaction from the driver (outside of putting your foot on the gas pedal that is) in order to work. But it is so much more complex than you think.

An automatic transmission system works by utilizing a series of gears that lock and unlock in order to change the gears of the vehicle. The transmission also uses a torque converter instead of a clutch to disconnect the transmission from the engine when the car needs to come to a stop.

The series of gears used actually have their own name. They are referred to as the Planetary Gear System (or Gear Set). The system has three main parts: the Ring Gear, the Planetary Gears and the Sun Gear. The Ring Gear is on the outer edge. The Planetary Gears are in the middle area (usually mounted to a carrier or plate). The Sun Gear is in the very center. The Planetary Gears rotate and revolve around the Sun Gear in the center and the Ring Gear on the outer edge.

 

planetary gear set

 

This system works by moving two of these parts, while keeping the third one still. By doing this, it can transmit the torque created by the engine to the wheels of the car, which, in turn, makes it move.

In addition to the above gear set, you also have what is called the Valve Body. It is what allows the automatic transmission of your car to smoothly shift gears as you are driving down the road. It is a hydraulic system that uses a pump to bring transmission fluid into the valve body. It then directs the fluid through a maze of channels and valves that, in turn, activate whatever gears are needed to shift to.

This maze is quite intricate and specialized. 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!

 

Food for Thought

 

I hope you were able to learn a little more this week about exactly how an Automatic Transmission works. In a nutshell, fluid is pumped through the system and through a specific valve which tells the vehicle which gear it needs to shift to.

Next week, we’ll continue to learn more about how an Automatic Transmission works. In truth, we’ve just begun to scratch the surface.

Until then, I’ll leave you with something to think about. We’ve all seen those big semi trucks that are always slow to start moving and we all curse and moan when we get stuck behind them at a stoplight. They typically have anywhere from 12 to 18 gears that their engine has to shift through to get moving. Just imagine the number of valves that transmission would need in order to shift up and down all of those gears IF they were an automatic transmission. How big would that engine be??!!??

 

Until next time,

Anthony’s Automotive

What do you mean my torque converter has gone bad? …and exactly what does that do again?

A Brief Introduction

My name is Anthony Pisa. I have been an auto mechanic for more than 23 years here on the Kenai Peninsula in Alaska. And, I have been a lover of all things automotive for way way longer than that. If there is anything I can talk about forever and a day, it’s cars …or fishing. But I’ll save my epic stories of that massive king salmon that almost got away for another day.

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Here at Anthony’s Transmission & Automotive Repair, we try our best to make sure that you understand exactly what is wrong with your car (if there is a problem) and how we will fix it for you. Even though you may not be a “car guy” like myself or any of my other mechanics, it’s important you truly understand at least the basics about your car. Especially when it comes to maintenance.

Each week on our website, I am going to give you basic information about a part or specific area of your car, define those special “automotive-speak” words related to that specific area of your car for you and hopefully give you a better understanding about the machine you love that gets you from Point A to Point B every day. If you have any specific part of your car that you are just in the dark about and I haven’t talked about yet, please comment below with your suggestion and I will see if we can make that the focus of a future post.

So, for this week, let’s talk Transmissions!

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Transmission-related Words

When you are trying to understand something, you want to make sure that you understand the words clearly that you hear or read. I can pretty much guarantee that if there was ever something in your life that you had trouble understanding, it was because there was a specific word that you didn’t understand and not necessarily the topic itself. As long as you have the meaning of and understand the words, you can understand anything.

With that in mind, this is why I am starting with our “automotive-speak” words first. This way when I describe how a specific part of your car works (or is supposed to work), you will understand exactly what it is that I am talking about. So let’s expand your automotive knowledge!

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

Torque – A twisting force that tends to cause rotation.

Converter – A person or thing that causes a change in form, character or function.

Torque Converter – A device that transmits or multiplies torque generated by an engine.

Driveshaft – A rotating shaft that transmits torque in an engine.

Driven Parts – The Wheels.

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).

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.

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.

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

Gasket – A shaped piece or ring of rubber or other material sealing the junction between two surfaces in an engine or other device.

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.

gear transmission

The Basics of a Vehicle Transmission

The whole purpose of the transmission in your car is to transfer power from the engine to the driveshaft and the rear wheels. Additionally, there are gears in the transmission that set the speed and torque of the wheels in relation to the speed and torque of the engine.

Transmissions come in two flavors: Automatic or Manual. Perhaps you have heard the term “Stick Shift”? This is another name for Manual.

A vehicle that has an Automatic Transmission is exactly what you think it would be based on the definition above. This kind of transmission automatically changes gears as the car moves with little to no interaction from the driver.

A vehicle that has a Manual Transmission requires 100% interaction from the driver. With the combination use of the clutch foot pedal and the stick shift, the driver manually changes the gears as the car moves.

Your transmission also requires a special fluid to help keep all of its parts working together. And this is a different fluid from oil or gasoline. Those fluids are for keeping other areas working that we will talk about in a future post.

So long story short… it is the Transmission of your car that turns the wheels and keeps you moving.

And as you can imagine, there are a few things that can go wrong with your transmission.

Common Transmission Problems & How to tell if it’s about to Die

Noise is your best friend when it comes to transmissions. A happy transmission literally purrs. You know that sound. It is definitely a happy sound. But a not so happy transmission? Is just like us when we don’t feel good. It whines. It grinds. It gets downright cranky.

A whining or humming noise coming from your car can indicate that your transmission is about to fail. This is typically caused by low transmission fluid levels. AND you could be low on fluid because you’ve developed a leak around a seal or a gasket.

Another type of problem is that your transmission refuses to go into gear or there feels like there is a delay in the car’s movement after you have shifted. This can indicate that the gears are being worn down and you definitely want to find out why.

And the last type of problem that I want to talk about is the dreaded shudder! You find yourself driving along and then all of a sudden your entire vehicle starts to shudder like you are driving on the roughest road ever, even though you are on a smooth highway. Remember the title of this post? That’s right! The dreaded shudder means your torque converter is going bad. It is no longer transferring power from the engine to your transmission. It is now causing your transmission to overheat. It is causing gears to slip. AND it is making your car work way harder than it should be, which, unfortunately, causes it to use more gas than it should.

Quick Final Thoughts

By now you should understand what your transmission is and does for – it keeps you moving. You also have some indicators to watch and listen for in case your transmission decides that it’s not happy. AND you have expanded your vocabulary and can start to talk “automotive-speak.” How cool is that?!

Please comment below if you have any questions or confusions about transmissions. OR, if you have a different area that you’d like me to talk about in a future post.

Next week, I’ll continue with the transmission theme and drive you into some more of the technical aspects about transmission.

 

Until next time….

Anthony’s Automotive