Early transmissions included the right-angle drives and other gearing in windmills, horse-powered devices, and steam engines, in support of pumping, milling, and hoisting.

Most modern gearboxes either reduce an unsuitable high speed and low torque of the prime mover output shaft to a more stable lower speed with higher torque, or do the opposite and provide a mechanical advantage (i.e increase in torque) to allow higher forces to be generated. Some of the simplest gearboxes merely change the physical direction in which power is transmitted.

Many typical automobile transmissions include the ability to select one of several different gear ratios. In this case, most of the gear ratios (simply called "gears") are used to slow down the output speed of the engine and increase torque. However, the highest gears may be "overdrive" types that increase the output speed.

Gearboxes have found use in a wide variety of different—often stationary—applications.

Transmissions are also used in agricultural, industrial, construction, mining and automotive equipment. In addition to ordinary transmission equipped with gears, such equipment makes extensive use of the hydrostatic drive and electrical adjustable-speed drives.

The simplest transmissions, often called gearboxes to reflect their simplicity (although complex systems are also called gearboxes in the vernacular), provide gear reduction (or, more rarely, an increase in speed), sometimes in conjunction with a right-angle change in direction of the shaft (typically in helicopters, see picture). These are often used on PTO-powered agricultural equipment, since the axial PTO shaft is at odds with the usual need for the driven shaft, which is either vertical (as with rotary mowers), or horizontally extending from one side of the implement to another (as with manure spreaders, flail mowers, and forage wagons). More complex equipment, such as silage choppers and snowblowers, have drives with outputs in more than one direction.

Regardless of where they are used, these simple transmissions all share an important feature: the gear ratio cannot be changed during use. It is fixed at the time the transmission is constructed.

For transmission types that overcome this issue, please see Continuously Variable Transmission, also known as CVT.

 Multi-ratio systems

Many applications require the availability of multiple gear ratios. Often, this is to ease the starting and stopping of a mechanical system, though another important need is that of maintaining good fuel economy.

 Automotive basics

The need for a transmission in an automobile is a consequence of the characteristics of the internal combustion engine. Engines typically operate over a range of 600 to about 7000 revolutions per minute (though this varies, and is typically less for diesel engines), while the car's wheels rotate between 0 rpm and around 1800 rpm.

Furthermore, the engine provides its highest torque outputs approximately in the middle of its range, while often the greatest torque is required when the vehicle is moving from rest or traveling slowly. Therefore, a system that transforms the engine's output so that it can supply high torque at low speeds, but also operate at highway speeds with the motor still operating within its limits, is required. Transmissions perform this transformation.

Most transmissions and gears used in automotive and truck applications are contained in a cast iron case, though sometimes aluminium is used for lower weight. There are three shafts: a mainshaft, a countershaft, and an idler shaft.

The mainshaft extends outside the case in both directions: the input shaft towards the engine, and the output shaft towards the rear axle (on rear wheel drive cars). The shaft is suspended by the main bearings, and is split towards the input end. At the point of the split, a pilot bearing holds the shafts together. The gears and clutches ride on the mainshaft, the gears being free to turn relative to the mainshaft except when engaged by the clutches.

Automobile includes manual, automatic or semi-automatic transmission.

 Manual

Main article: manual transmission

Manual transmission come in two basic types:

• a simple but rugged sliding-mesh or unsynchronized / non-synchronous system, where straight-cut spur gear sets are spinning freely, and must be synchronized by the operator matching engine revs to road speed, to avoid noisy and damaging "gear clash",
• and the now common constant-mesh gearboxes which can include non-synchronised, or synchronized / synchromesh systems, where diagonal cut helical (and sometimes double-helical) gear sets are constantly "meshed" together, and a dog clutch is used for changing gears. On synchromesh boxes, friction cones or "synchro-rings" are used in addition to the dog clutch.

The former type is commonly found in many forms of racing cars, older heavy-duty trucks, and some agricultural equipment.

Manual transmissions dominate the car market outside of North America. They are cheaper, lighter, usually give better performance, and fuel efficiency (although the latest sophisticated automatic transmissions may yield results slightly closer to the ones yielded by manual transmissions). It is customary for new drivers to learn, and be tested, on a car with a manual gear change. In Malaysia, Denmark and Poland all cars used for testing (and because of that, virtually all those used for instruction as well) have a manual transmission. In Japan, Philippines, Germany, Israel, the Netherlands, New Zealand, Austria, the UK ^[1][2], Ireland^[2], Sweden, France, Australia, Finland and Lithuania , a test pass using an automatic car does not entitle the driver to use a manual car on the public road; a test with a manual car is required.^{[citation needed]} Manual transmissions are much more common than automatic transmissions in Asia, Africa, South America and Europe.

 Non-synchronous

Main article: Non-synchronous transmissions

There are commercial applications engineered with designs taking into account that the gear shifting will be done by an experienced operator. They are a manual transmission, but are known as non-synchronized transmissions. Dependent on country of operation, many local, regional, and national laws govern the operation of these types of vehicles (see Commercial Driver's License). This class may include commercial, military, agricultural, or engineering vehicles. Some of these may use combinations of types for multi-purpose functions. An example would be a PTO, or power-take-off gear. The non-synchronous transmission type requires an understanding of gear range, torque, engine power, and multi-functional clutch and shifter functions. Also see Double-clutching, and Clutch-brake sections of the main article at non-synchronous transmissions.

To order a transmission, please visit www.GotEngines.com or www.GotTransmissions.com

Or you can call Toll Free 1-877-268-0664

First, before you attempt this procedure, go buy a copy of the Haynes manual. The Haynes procedure for this job is quite good and I will generally follow their order of operations.

What you should buy beforehand depends on a) how well-funded you are and b) how much time you have. If you have ample amounts of both a and b then you should go whole hog. Buy a new clutch disc and pressure plate, as well as a new clutch release bearing and pilot bearing. If you need to replace fuel lines, when the engine is out is the time to do it, especially if you're dealing with the fuel rail in the enVanagon, 1980-1983 air-cooled with manual transmission only. This will also loosely apply to late ('75-'79) Buses, but there are many different details, and the devil is in the details, as they say. This procedure is for the Type 4 2.0L fuel-injected engine, for all you non-US folks who had other engine choices.

First, before you attempt this procedure, go buy a copy of the Haynes manual. The Haynes procedure for this job is quite good and I will generally follow their order of operations.

What you should buy beforehand depends on a) how well-funded you are and b) how much time you have. If you have ample amounts of both a and b then you should go whole hog. Buy a new clutch disc and pressure plate, as well as a new clutch release bearing and pilot bearing. If you need to replace fuel lines, when the engine is out is the time to do it, especially if you're dealing with the fuel rail in the engine compartment or the injectors themselves. Also, if those four big fat short hoses on your intake manifold are shot, now's a good time to fix that. Anything else you think you should do with the engine out, buy what you need to do it.

This procedure does not concern itself with why you have to remove your engine. I'm just gonna tell you how. I'm telling you how to remove the engine and transmission as a unit from the car, and then separate them on the ground. It seems to be a little easier to do it this way. For this job you will need a helper. Period. You will also need a sturdy floorjack, preferably some kind of dolly you can set the engine/tranny on or a couple sets of jackstands. I had the privilege of performing this procedure with access to an automotive lift. You will also want some sort of largish piece of wood, to spread out the weight of the engine on the floorjack's saddle. If you don't have lots of jackstands or a dolly, you can always set the engine down on some sort of tarp or old piece of carpet. Be creative.

Well now let's get started. I'm not going to quote a list of tools needed here, because it would take too much time. I'll just mention them as the need for them comes up.

The first step is to disconnect the battery ground strap. Don't forget this important step! Easy enough...

Next you want to remove the air cleaner assembly. Get your Philips head screwdriver and undo the clamp that holds the rubber S-boot in the engine compartment to the fuel injection system's air flow meter. Separate the boot from the AFM. Next unplug the FI wiring harness from the AFM. Grasp the plastic plug and pull straight back on it. Next remove the charcoal canister hose from the air cleaner housing. Finally, you will find that on top of the air cleaner housing there is a clip that holds the air cleaner assembly to the body of the van. Unhook this clip (it is similar in operation to the clips that hold the air cleaner assembly halves together). Once you have all this stuff removed, wiggle the air cleaner assembly out of there and set it somewhere safe.

Now check down behind the alternator (toward the front of the van) and see where the wiring connects. You will find a plastic connector plugged into the alternator. Unplug this. Also you will find another single wire coming from the alternator that has a connector plug near the alternator. Unplug this wire too.

Now remove the rubber bellows for the heater blower. You can just pull it out of there.

Next detach the big vacuum hose for the power brakes at the manifold. Just pull it off of the left side of the manifold.

Disconnect the wiring from the ignition coil. On my van, the coil is mounted to the left side wall in the engine compartment. You need to determine which wires must be removed for the engine to come out. The wire to the condenser must be removed as well as the white wire to the fuel injection wiring harness. There may be others that I can't remember right now. Basically any wires that go to the engine must be removed. Label them so that you know what terminal to place them on when you have to put it back together. Also, disconnect the wire from the oil pressure switch and label it. The oil pressure switch is located immediately forward of the distributor, buried beneath the tin.

Disconnect the wiring plug from the electronic control unit. The ECU is located on the right side of the engine compartment, it's that electronic box with the huge plug going to it. One end of this plug has a spring lever -- push the lever in while simultaneously pulling that end of the plug away from the ECU. Also disconnect the right-side wiring plug from the double relay (mounted to the left side of the firewall). The left-side plug can remain attached to the relay. Disconnect also the wiring plug to the series resistors, mounted near the double relay. Finally disconnect the vacuum hose to the deceleration valve (large cylindrical device mounted to the firewall).

Additionally, disconnect the accelerator cable from the engine. It passes through a barrel-type clamp, so loosen the bolt and pull the cable free, then push it out of the engine compartment, toward the front of the van. I seem to remember the bolt being 8mm.

Now is a good time to jack up the rear of the vehicle and support it on jackstands. Give yourself plenty of room to get the engine out -- don't forget to take into account the minimum height of the floorjack!

Now you have to disconnect the fuel lines. Crawl under the van and notice where the fuel lines pass through the breast tin. There underneath the van you will see where the rubber hoses connect to the metal fuel rail. There should be clamps on each end of the section of rubber hose -- if not, you need to buy some. If the rubber hose looks at all questionable, be sure to replace it with quality FUEL-INJECTION RATED hose. A tip here is to take a pair of locking pliers like Vice-Grips and clamp on the rubber fuel hose before removing it to keep the gas in the tank from siphoning out. It helps to own two pairs of locking pliers. You also may want to have a pencil or bolt or golf tee handy to plug the fuel line after removal. Remove both fuel lines, on a fuel-injected van there is a supply line and a return line.

Now you have to undo the wiring from the starter. Remove the 13mm nut from terminal 30 on the back of the solenoid and remove all the wires. Put a zip-tie through all the ring connectors of those wires so you don't lose any. Then pull the two push-on wires from the solenoid, labeling each one.

Now you have to unclamp the heater flapper boxes from the short pipes that lead from the flappers to the heat exchangers. Unclamp them at the flapper end. There will be some sort of clamp holding it on, probably rusty as hell. Do what you have to do, but the clamps must come off. Once the clamps are loose, unseat the flappers from the heat pipes.

Now you get to have fun with CV joints. You will need to put the transmission in neutral and remove the parking brake. Find out what sort of CV bolts you have. You will either have 6mm allen-head CV bolts (stock) or a set of 12-point bolts (Porsche replacement). You CANNOT use an allen head bit on the 12-point bolts, you will strip them out and will be up sh*t creek. Whatever you have, buy the appropriate bit that will fit on a ratchet. Once you've got the tool ready to go, loosen the bolts on each axle that hold the driveshaft to the transmission. You will need to to 2 or 3 bolts and then rotate the wheels to get the rest. Once you've done that, withdraw the joints from the tranny and let them hang (actually, it would be better to support the axles with coat hangers or something but do what you have to do). You also should wrap the now-open CV joints with a plastic bag and rubber band so they don't get grit in them.

Now you get to deal with the clutch slave cylinder. On the left side of the transmission you will find it. There are two bolts that hold the slave cylinder to the transmission and then there is another bolt more toward the front of the car that holds the hydraulic pipe support bracket to the transmission. You need to undo the bolt to the support bracket, and then undo the two bolts that hold the slave cylinder to the transmission. They are nuts and bolts, so a helper will come in handy here. It's easiest to reach them through the left rear wheel well, while someone else underneath holds the nut to keep it from turning. Once you've got the slave cylinder loose, set it aside somewhere and support it so it doesn't stress the hydraulic hose.

Now, look at the transmission nosecone, where the shift rod attaches. You will see that at the end of the shift rod is a big 19mm nut. Remove this nut from the shift rod and pop the shift rod forward so it is free of the transmission.

While you're down there, remove the ground strap between the transmission and frame. Don't forget! Also disconnect the two wires from the back-up light switch. You don't have to label them, it doesn't matter which terminal of the switch they go to.

OK, now take your piece of scrap wood and put it on the saddle of your floorjack. Now try to center the wood under the engine/tranny and jack it up so that the jack is just supporting the weight of the engine/tranny.

Now get under and head up to the front of the transmission. Find the front transmission mount. There are two ways to undo this, and I chose the way that I thought would be easier to put back together later. You will see that four bolts hold the transmission mount to the frame. Undo these four bolts and put them in a safe place.

Now crawl back out and find where the rear engine bearer bar bolts to the frame on each side of the van with 2 13mm bolts/nuts per side. Undo all of these bolts and put them in a safe place. Now the only thing holding the engine/transmission in is the jack.

Do one last check and make sure you've disconnected everything. SLOWLY lower the engine and transmission. It will usually want to tilt one way or another so have your helper steady it as you control the jack. Slowly lower it while checking to make sure nothing will be crushed or broken by the engine -- WATCH THOSE CV JOINTS!

Once you've got the engine lowered so it will clear the body, slide it back and out of the way -- or, if you're lucky enough to be using a lift, just raise the body up out of the way.

Now you need to set the engine and transmission down. If you have spare jackstands around, you can set up a tripod of sorts by putting a jackstand under each side of the bearer bar and then another one under the transmission. If you have a dolly you can gently transfer the engine to that or if you have a soft surface on the ground, you can do that too.

Now you can separate the engine and transmission. There are two bolts at the top and two nuts on studs at the bottom. All are 17mm. The top right one is also the top mounting bolt for the starter. Once all nuts and bolts are removed and stored in a safe place (don't lose the washers) then the engine can be removed from the transmission. If you have the engine and transmission resting on jackstands, then you will need to move the one under the transmission to somewhere under the engine case so everything won't come crashing down when you pull the transmission. If you or your helper is sufficiently strong, then one of you can steady the engine while the strong one pulls the transmission straight back and sets it gently on the ground. If not, you can use the floorjack to help. The transmission weighs about 70 pounds.

While the engine is out you can do whatever you need to do that led you to remove the engine in the first place. You also may want to take this time to clean out the engine compartment, and anything on the engine that looks like it would be easier with the engine out.

Installation really is the reverse of removal. The tricky part comes in aligning the engine and transmission splines for mating the two and in aligning the engine and transmission upon putting them back into place -- that is, aligning the bearer bar with the holes the bolts go through and aliging the front transmission mount with its holes. It takes some patience but once you've got it aligned then thread the bolts and nuts and then re-attach everything you disconnected. That's it.

gine compartment or the injectors themselves. Also, if those four big fat short hoses on your intake manifold are shot, now's a good time to fix that. Anything else you think you should do with the engine out, buy what you need to do it.

This procedure does not concern itself with why you have to remove your engine. I'm just gonna tell you how. I'm telling you how to remove the engine and transmission as a unit from the car, and then separate them on the ground. It seems to be a little easier to do it this way. For this job you will need a helper. Period. You will also need a sturdy floorjack, preferably some kind of dolly you can set the engine/tranny on or a couple sets of jackstands. I had the privilege of performing this procedure with access to an automotive lift. You will also want some sort of largish piece of wood, to spread out the weight of the engine on the floorjack's saddle. If you don't have lots of jackstands or a dolly, you can always set the engine down on some sort of tarp or old piece of carpet. Be creative.

Well now let's get started. I'm not going to quote a list of tools needed here, because it would take too much time. I'll just mention them as the need for them comes up.

The first step is to disconnect the battery ground strap. Don't forget this important step! Easy enough...

Next you want to remove the air cleaner assembly. Get your Philips head screwdriver and undo the clamp that holds the rubber S-boot in the engine compartment to the fuel injection system's air flow meter. Separate the boot from the AFM. Next unplug the FI wiring harness from the AFM. Grasp the plastic plug and pull straight back on it. Next remove the charcoal canister hose from the air cleaner housing. Finally, you will find that on top of the air cleaner housing there is a clip that holds the air cleaner assembly to the body of the van. Unhook this clip (it is similar in operation to the clips that hold the air cleaner assembly halves together). Once you have all this stuff removed, wiggle the air cleaner assembly out of there and set it somewhere safe.

Now check down behind the alternator (toward the front of the van) and see where the wiring connects. You will find a plastic connector plugged into the alternator. Unplug this. Also you will find another single wire coming from the alternator that has a connector plug near the alternator. Unplug this wire too.

Now remove the rubber bellows for the heater blower. You can just pull it out of there.

Next detach the big vacuum hose for the power brakes at the manifold. Just pull it off of the left side of the manifold.

Disconnect the wiring from the ignition coil. On my van, the coil is mounted to the left side wall in the engine compartment. You need to determine which wires must be removed for the engine to come out. The wire to the condenser must be removed as well as the white wire to the fuel injection wiring harness. There may be others that I can't remember right now. Basically any wires that go to the engine must be removed. Label them so that you know what terminal to place them on when you have to put it back together. Also, disconnect the wire from the oil pressure switch and label it. The oil pressure switch is located immediately forward of the distributor, buried beneath the tin.

Disconnect the wiring plug from the electronic control unit. The ECU is located on the right side of the engine compartment, it's that electronic box with the huge plug going to it. One end of this plug has a spring lever -- push the lever in while simultaneously pulling that end of the plug away from the ECU. Also disconnect the right-side wiring plug from the double relay (mounted to the left side of the firewall). The left-side plug can remain attached to the relay. Disconnect also the wiring plug to the series resistors, mounted near the double relay. Finally disconnect the vacuum hose to the deceleration valve (large cylindrical device mounted to the firewall).

Additionally, disconnect the accelerator cable from the engine. It passes through a barrel-type clamp, so loosen the bolt and pull the cable free, then push it out of the engine compartment, toward the front of the van. I seem to remember the bolt being 8mm.

Now is a good time to jack up the rear of the vehicle and support it on jackstands. Give yourself plenty of room to get the engine out -- don't forget to take into account the minimum height of the floorjack!

Now you have to disconnect the fuel lines. Crawl under the van and notice where the fuel lines pass through the breast tin. There underneath the van you will see where the rubber hoses connect to the metal fuel rail. There should be clamps on each end of the section of rubber hose -- if not, you need to buy some. If the rubber hose looks at all questionable, be sure to replace it with quality FUEL-INJECTION RATED hose. A tip here is to take a pair of locking pliers like Vice-Grips and clamp on the rubber fuel hose before removing it to keep the gas in the tank from siphoning out. It helps to own two pairs of locking pliers. You also may want to have a pencil or bolt or golf tee handy to plug the fuel line after removal. Remove both fuel lines, on a fuel-injected van there is a supply line and a return line.

Now you have to undo the wiring from the starter. Remove the 13mm nut from terminal 30 on the back of the solenoid and remove all the wires. Put a zip-tie through all the ring connectors of those wires so you don't lose any. Then pull the two push-on wires from the solenoid, labeling each one.

Now you have to unclamp the heater flapper boxes from the short pipes that lead from the flappers to the heat exchangers. Unclamp them at the flapper end. There will be some sort of clamp holding it on, probably rusty as hell. Do what you have to do, but the clamps must come off. Once the clamps are loose, unseat the flappers from the heat pipes.

Now you get to have fun with CV joints. You will need to put the transmission in neutral and remove the parking brake. Find out what sort of CV bolts you have. You will either have 6mm allen-head CV bolts (stock) or a set of 12-point bolts (Porsche replacement). You CANNOT use an allen head bit on the 12-point bolts, you will strip them out and will be up sh*t creek. Whatever you have, buy the appropriate bit that will fit on a ratchet. Once you've got the tool ready to go, loosen the bolts on each axle that hold the driveshaft to the transmission. You will need to to 2 or 3 bolts and then rotate the wheels to get the rest. Once you've done that, withdraw the joints from the tranny and let them hang (actually, it would be better to support the axles with coat hangers or something but do what you have to do). You also should wrap the now-open CV joints with a plastic bag and rubber band so they don't get grit in them.

Now you get to deal with the clutch slave cylinder. On the left side of the transmission you will find it. There are two bolts that hold the slave cylinder to the transmission and then there is another bolt more toward the front of the car that holds the hydraulic pipe support bracket to the transmission. You need to undo the bolt to the support bracket, and then undo the two bolts that hold the slave cylinder to the transmission. They are nuts and bolts, so a helper will come in handy here. It's easiest to reach them through the left rear wheel well, while someone else underneath holds the nut to keep it from turning. Once you've got the slave cylinder loose, set it aside somewhere and support it so it doesn't stress the hydraulic hose.

Now, look at the transmission nosecone, where the shift rod attaches. You will see that at the end of the shift rod is a big 19mm nut. Remove this nut from the shift rod and pop the shift rod forward so it is free of the transmission.

While you're down there, remove the ground strap between the transmission and frame. Don't forget! Also disconnect the two wires from the back-up light switch. You don't have to label them, it doesn't matter which terminal of the switch they go to.

OK, now take your piece of scrap wood and put it on the saddle of your floorjack. Now try to center the wood under the engine/tranny and jack it up so that the jack is just supporting the weight of the engine/tranny.

Now get under and head up to the front of the transmission. Find the front transmission mount. There are two ways to undo this, and I chose the way that I thought would be easier to put back together later. You will see that four bolts hold the transmission mount to the frame. Undo these four bolts and put them in a safe place.

Now crawl back out and find where the rear engine bearer bar bolts to the frame on each side of the van with 2 13mm bolts/nuts per side. Undo all of these bolts and put them in a safe place. Now the only thing holding the engine/transmission in is the jack.

Do one last check and make sure you've disconnected everything. SLOWLY lower the engine and transmission. It will usually want to tilt one way or another so have your helper steady it as you control the jack. Slowly lower it while checking to make sure nothing will be crushed or broken by the engine -- WATCH THOSE CV JOINTS!

Once you've got the engine lowered so it will clear the body, slide it back and out of the way -- or, if you're lucky enough to be using a lift, just raise the body up out of the way.

Now you need to set the engine and transmission down. If you have spare jackstands around, you can set up a tripod of sorts by putting a jackstand under each side of the bearer bar and then another one under the transmission. If you have a dolly you can gently transfer the engine to that or if you have a soft surface on the ground, you can do that too.

Now you can separate the engine and transmission. There are two bolts at the top and two nuts on studs at the bottom. All are 17mm. The top right one is also the top mounting bolt for the starter. Once all nuts and bolts are removed and stored in a safe place (don't lose the washers) then the engine can be removed from the transmission. If you have the engine and transmission resting on jackstands, then you will need to move the one under the transmission to somewhere under the engine case so everything won't come crashing down when you pull the transmission. If you or your helper is sufficiently strong, then one of you can steady the engine while the strong one pulls the transmission straight back and sets it gently on the ground. If not, you can use the floorjack to help. The transmission weighs about 70 pounds.

While the engine is out you can do whatever you need to do that led you to remove the engine in the first place. You also may want to take this time to clean out the engine compartment, and anything on the engine that looks like it would be easier with the engine out.

Installation really is the reverse of removal. The tricky part comes in aligning the engine and transmission splines for mating the two and in aligning the engine and transmission upon putting them back into place -- that is, aligning the bearer bar with the holes the bolts go through and aliging the front transmission mount with its holes. It takes some patience but once you've got it aligned then thread the bolts and nuts and then re-attach everything you disconnected. That's it.

To Order an Engine or Transmission Replacement, Please Call 1-877-268-0664 or visit GotEngines.com

The simplest transmissions are manual transmissions, and consist of a system of interlocking gearwheels. These wheels are arranged so that by operating a lever the driver can choose one of several ratios of speed between the input shaft and the output shaft. These ratios are called gears, first gear being the arrangement that gives the lowest output speed, second gear the next lowest, and so forth. To allow smooth shifting from one gear to another, a clutch is provided to disengage the engine from the transmission. The commonly used dry single disk clutch has a steel disk with a friction lining that is sandwiched between a flywheel on the engine shaft and a pressure plate on the transmission input shaft. When the driver takes his foot off the clutch pedal, springs squeeze the friction disk into the space between the flywheel and the pressure plate, enabling the engine shaft to turn the transmission.

For many cars and for normal driving conditions a transmission with three forward gears and one reverse gear is sufficient. In cars having small engines transmissions with four or five forward speeds are used; racing cars often have as many as six forward speeds. A synchromesh transmission is a manual transmission in which all forward gear wheels are held in mesh at all times. Used on most American cars with a manual transmission, it allows the driver to shift gears more smoothly and makes the car run more quietly.

The automatic transmission, introduced in 1939, switches to the optimum gear without driver intervention except for starting and going into reverse. The type of automatic transmission used on current American cars usually consists of a fluid device called a torque converter and a set of planetary gears. The torque converter transmits the engine's power to the transmission using hydraulic fluid to make the connection. For more efficient operation at high speeds, a clutch plate is applied to create a direct mechanical connection between the transmission and the engine.

The introduction of microprocessor-controlled electronic sensors has enhanced the performance of automatic transmissions still more. Data about engine speed, exhaust pressure, and other performance characteristics are sent to a processor that controls the changing of gears and the clutch plate in the torque converter via electrical switches, or solenoids. New approaches to transmission design combine the best features of manual and automatic transmissions to provide more efficient ways of channeling engine power to the wheels. A manumatic transmission is an automatic transmission with an added manual-shift mode; typically, a floor-mounted shifter offers an alternative selector path supplemented by buttons mounted on the steering wheel. A continuously variable transmission (CVT) uses a belt that connects two variable-diameter pulleys to provide an unlimited number of ratio changes and uninterrupted power to the wheels; CVT transmissions offer better fuel efficiency than conventional automatic transmissions, which change the transmission ratio by shifting gears. A sequential manual gearbox (SMG), developed for Formula One cars, uses computer-controlled actuators to operate the clutch and change gears when prompted by the driver; both manual and automatic modes are possible, and there is no clutch pedal. The dual clutch transmission (DCT), also called the direct shift gearbox (DSG), substitutes dual clutches for the conventional single-sided clutch to transfer power from the engine through two parallel paths; the gearbox features two sets of gears, identical to those in conventional manual transmissions—one set being the odd gears (1st, 3rd, 5th) and the other the even gears (2nd, 4th, 6th)—the gears must be shifted in sequence, and power to the wheels is never interrupted.

To purchase a new,used, or remanufactured transmission for a cheap price without comprimising a great warranty, please call Toll Free 1-877-268-0664 or visit GotEngines.com 

I find the weekly list of top downloaded TV torrents fascinating.

Last week the top three shows were TOP GEAR, WEEDS and STARGATE ATLANTIS.

Unlike the classic Neilson numbers, the torrent list is much more international.  It also clearly has a bent toward a younger, more tech-savvy audience.  However, one would be wrong to ignore how important these types of fan can be to a show that is not viewed as traditionally popular at a given network.

The trick for the networks is to figure out how to lure that crowd away from the pirated torrents and toward their own streams.

Of course, that would mean real innovation and change so don't expect anything soon.

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Il s'agit d'un Jeep Cherokee Chief, dont la carrosserie semble plutôt propre, puisque c'est un modèle de 1987.

Arrangez ça comme vous voulez, mais il y a une attache de remorque... à l'avant!  Le sympathique propriétaire précédent, qui habite Saint-Jean-sur-Richelieu, m'a précisé qu'il se servait du véhicule principalement pour tirer son bateau.  Ceux qui manoeuvrent souvent des remorques savent bien que si une telle installation est plutôt inutile sur la route, elle est très pratique sur des terrains fermés,  car il est plus facile de déplacer une remorque sans avoir à constamment tourner la tête vers l'arrière.  Mais ne vous en faites pas; je lui trouverai bien une utilisation.  En passant, la flaque d'huile, sous le pare-chocs, est une gracieuseté de la pompe de servo-direction, qui a été remplacée depuis la prise de ces photos.

Le toit et le hayon arrière, ainsi que le capot, qui porte toujours les bandes décoratives propres à ce modèle, sont encore recouverts de la peinture d'origine, qui date de 21 ans.  Les côtés ont toutefois déjà été repeints.

Autre détail original, le lettrage, à l'arrière, qui montre bien qu'il s'agit d'un Cherokee Chief.  Évidemment, une autre attache de remorque est installée, au bon endroit, cette fois.

Si l'extérieur est encore très potable, l'intérieur accuse davantage le poids des années.

Voilà le secret de la longévité de sa carrosserie; il a été traité, pendant plusieurs années, à l'huile antirouille.

La blogue-mobile est équipée d'une boîte manuelle à 5 rapports.  On constate, une fois de plus, à la vue du soufflet du levier de transmission, qu'il reste beaucoup de petits détails à fignoler, du côté de la finition intérieure.

À défaut de proposer la climatisation, ce véhicule est toutefois muni d'une radio AM/FM de qualité, à façade détachable, de marque JVC, et doté d'une télécommande.  Elle lit également les CD, CD-RW et les MP3.

Parmi les trucs à fignoler, un compresseur à air, dont on voit ici la commande, qui permettra, une fois redevenu fonctionnel, l'installation d'amortisseurs pneumatiques.

Voici l'une des principales raisons pour laquelle j'ai choisi ce véhicule.  Il est doté d'une boîte de transfert Selec-Trac, qui permet le passage de 2 à 4 roues motrices à la volée.

Le tableau de bord est passablement complet, avec tous les indicateurs, que je préfère de beaucoup aux lampes-témoin qui, malheureusement, équipent encore beaucoup de véhicules américains.

Au prix où je l'ai payée, lequel comprend également quatre très bons pneus d'hiver, montés sur des jantes en acier, je ne suis pas sans me douter qu'il y aura des réparations à effectuer.  L'ancien propriétaire a été tout à fait honnête, et toutes les réparations effectuées à date concernent des problèmes qu'il m'avait révélé.  À date, j'ai remplacé la pompe de servo-direction, le radiateur, et le ventilateur du système de chauffage, le tout avec succès.  Présentement, elle est à Saint-Lin--Laurentides, où on procède à la rénovation du plancher, ainsi qu'à quelques trucs sur la carrosserie.  À son retour, j'aurai à remplacer un joint d'étanchéité au niveau de la boîte de direction, qui vient de commencer à fuir.  Ensuite, ce sera la tournée d'entretien; vidange d'huile à moteur, de transmission manuelle, des deux différentiels et de la boîte de transfert.  Bref, de quoi m'amuser pendant plusieurs week-ends.

Par contre, comme il s'agit pour moi d'un second véhicule (j'ai déjà une voiture sous-compacte), je n'ai pas de pression, au niveau de l'entretien et des réparations.  J'y vais en fonction de mon budget, et de mes temps libres.  J'ai toujours aimé "bizouner" la mécanique, et cette Jeep me permet de le faire, et ce sans le stress d'avoir à tout remonter rapidement, pour cause de nécessité.

Quant à la réserve de photos, elle commence à tirer à sa fin, ce qui veut dire que je devrai repartir à la chasse aux images.  Je ne vais pas vous révéler mes intentions en détails, de peur de me pas remplir mes engagements.  La chasse aux photos est souvent sujette aux tribulation de Dame Nature, dont la météo est plus incertaine que jamais, cette année.  Mais il me reste mon dernier coup de tête, incidemment sous la pluie, et en plein territoire des moustiques, soit cet échangeur en devenir, dont la vocation fut transformée, par la force des choses, en passe à chevreuils.  Un indice de plus?  C'est dans la région des Cantons-de-l'Est, tout près de celle du Centre-du-Québec.

Vous voulez plus de détails, encore?  Une seule façon de faire; restez branchés!

J'aimerais pouvoir dire au lieu de couvain : un naissain, comme
pour les huîtres et les moules. On pourrait alors schématiser ainsi une génération d'abeilles en un bref poème de deux vers à rime riche et originale (digne de l'Oulipo…) :

Au début un naissain

Un essaim à la fin.

Entre les deux le temps d'une génération.
Cette homophonie soulignerait le but simple d'une vie animale : transmettre à l'identique. Comme chez les abeilles, depuis 4 millions d'années… Et le miel qu'elles distillent est si parfait qu'il n'a nullement besoin de conservateur, puisqu'on en a même retrouvé, intact, dans des couches géologiques datant du secondaire…

Nous, humains, devons également transmettre, mais aussi améliorer, tout un patrimoine culturel, toute une civilisation, une infinité de savoir faire, de savoir être, de savoir apprendre…

Aussi, à l'exemple des abeilles, nous devrions considérer notre couvain, nos tout petits, comme notre bien le plus précieux, comme ce qui, de « larves » démunies pourrait devenir « abeilles » parfaites.

Au prix de beaucoup de soins, de tendresse, de sollicitude, d'amour et de confiance absolue dans leur infinie richesse potentielle.

La seule différence étant que l'abeille est génétiquement programmée à se reproduire à l'identique de génération en génération, à « materner » aujourd'hui comme toujours, sans la moindre variante. Notre génome humain, lui, laisse tant de degrés de liberté que s'y glisse la possibilité d'infinis façonnages et progrès individuels, mais aussi d'autant de risques de déclins et d'échecs et de souffrances en cas de négligence ou d'indisponibilité. Et du coup est engagée notre immense responsabilité de formateurs, de passeurs.

Couvons avec admiration et tendresse notre merveilleux couvain. Son temps de dépendance modelable et perfectible est très bref. Le petit bolide passionné des premiers mois ralentit vite et l'adulte « fini » (c'est souvent hélas le cas) fait du sur-place quand il ne recule pas.

I think I only have a few minutes here before we leave, which means no more correspondence until Saturday at least.  My regur

...

That was all that was, apparently, of a correspondence post I was trying to make last...Thursday.  I had written over a paragraph-and-a-half more before I hit "send", whereupon I discovered that McDonald's had dropped its hammer and shut me out from the free connection I had found.  Turns out the "att" network was part of McDonald's somehow.  Lucky for me, I guess, that portion of the post was saved, thanks to beautiful, beautiful Wordpress.

The reason for my correspondence, as I think I might have mentioned but am not sure and am not going to go back to check right now, was that I was in a special place, a magical place, without Internet.  The place is called Zook & Lyter's.  I've been going there ever since I was born, every year, once a year.  I love it there.  Plenty of people, like my brother, may find it boring.  But I just love it up there.  It's the most serene and beautiful place I've ever been, and there's nothing big to it.  It's not a tourist trap.  It's just, there.  Seven cabins by the Juniata River.  A see-saw, sandbox, some swings, some monkey bars, all for the kiddies.  Two docks, canoe rentals, a nearby access area; it's great for fishing, something else we used to do every year with my now late Poppop.  But I don't recommend the sandbox.  It's dirty in there, man.  Beautiful water, beautiful tree-covered mountains just beyond it, beautiful fields and landscapes in general.  White squirrels, though we didn't see any this year.  We did see a skunk though.  And I drove!

I really love Zook & Lyter's.  I'll never get tired of it.  I got the raw inspiration that I expected I'd get when I was up there, but I couldn't make anything of it.  It was too raw.  It came and went before the week was over.  Most of the time I played Super Nintendo games on the laptop.  Though, I did get a summer AP Art assignment started.  I just need to shade some stuff now.

There are Amish there, too.  Now, everytime I say that to someone, they think, "Oh yeah, Lancaster".  NO.  It's not Lancaster, damn it.  It's about an hour or two WEST of Lancaster.  Yeah, undisturbed Amish.  People misunderstand the Amish.  They don't like photos because it's too vain to have a photo taken, not because it'll steal their soul.  They can use electricity, as long as things are battery-operated.  They have a phone.  I mean, they do business with non-Amish.  They get rides in cars.  You don't know Amish.

Or maybe you do.  I don't know.  I don't know you.