Tag Archives: Manual Transmissions

Transmission Types and History of Development

From starting with manual transmissions, to the introduction of automatic transmissions in 1939 – learn about the evolution of the modern transmission.

The transmission in automobiles is a system of parts usually contained within a housing, connecting the engine to the wheels. Suitable torque, or turning force, is generated by the engine only within a narrow range of engine speeds, i.e., rates at which the crankshaft is turning. However, the wheels must turn with suitable torque over a wide range of speeds. While its speed is held roughly constant, the engine turns an input shaft on the transmission whose output shaft can be adjusted to turn the wheels at an appropriate speed.

Manual Transmission

The manual transmission is the simplest (and earliest) of 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.

Synchromesh Transmission

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.

Automatic Transmission

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.

Manumatic Transmission

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.

Continuously Variable Transmission

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.

Sequential Manual Gearbox

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.

Dual Clutch Transmission

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.

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Shake, Rattle, and Roll: Is Your Transmission Noisy in Neutral?

Troubling noises emanating from beneath your hood should not be neglected

Is your vehicle’s manual transmission noisy in neutral? Do you hear humming, buzzing, or whining noises when you let the clutch out in neutral? If your answer to these questions is ‘yes’, your vehicle’s transmission should be inspected by a certified technician, as it may be a warning sign that your transmission is failing.

Furthermore, if you hear unusual noises as you shift while accelerating, or if you feel your car shuddering when changing gears or find changing gears laborious, it’s possible your clutch is worn out.

For automatic transmissions, the warning signs are similar: the car struggles to change gears or gears are slipping, you’re unable to shift into reverse, or you notice a distinct burning smell while driving.

What Causes a Noisy Transmission?

Being proactive with preventative maintenance is your best defence to prolong the life of your manual or automatic transmission. But even if you are, and you follow the recommended best practices to prevent a transmission breakdown, there are no guarantees that an electronic or mechanical failure won’t occur.

Regarding a noisy transmission, the trouble could range from a lack or loss of transmission fluid; the incorrect fluid type was inserted into your transmission, gears or bearings have worn down, or there are damaged gear teeth.

If you suspect your vehicle’s transmission isn’t performing properly, or if you have questions about preventative transmission maintenance, contact us. Take advantage of our free 21-point multi-check inspection and avoid the cost and aggravation associated with a failing transmission.

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Transmission Additives- Do They Work?

When it comes to transmission additives, why are the shelves at most auto suppliers loaded with “miracle” fluids that will allegedly make up for a prior lack of maintenance? Can these additives actually fix a transmission?

Let`s be frank. There are no “miracle” fluids that can substitute for preventative maintenance, this is just common sense. The only way to repair a transmission problem is to properly diagnose it by road testing, scanning the computer, and removing the pan for inspection.

Fluid additives do offer limited benefits for vehicles being used for certain tasks or in certain climates or weather conditions. Here we’ll cover the basics of ATF importance, why most vehicles don’t require these additives and the instances when ATF additives can help.

First of all, a refresher on why we need ATF in the first place. ATF is essential to the smooth running of a vehicle’s transmission. ATF has lubricants, protectants and detergents that protect the transmission and keeps it in good working order.

Generally, most vehicles are simply used to take people to work, school or shopping so don’t need ATF additives. For these everyday activities the manufacturer recommended automatic transmission fluid alone should be enough to protect the transmission in most situations they will encounter. As long as the owner of the vehicle takes the time to makes sure there is enough transmission fluid in it and they change the transmission fluid when it is dirty there should be no need for an automatic transmission fluid additive.

There is no fluid that will:

  • unclog plugged filters
  • free-up stuck valves/solenoids
  • reduce internal corrosion
  • improve shift feel/firmness
  • prolong the life of your transmission
  • replace the friction material on your transmission’s clutch plates
  • put the teeth back on the stripped gears

Keep in mind that most vehicle manufacturers have warnings in their owner’s manuals stating: “Do not use supplemental oil additives, cleaners or other treatments. They are unnecessary and could lead to damage that is not covered by warranty.” Or: “Using supplemental additives is generally unnecessary and can even be harmful. One should never use an additive to attempt to fix a mechanical problem.”

Who could benefit from using additives?

A small majority of vehicle owners could potentially benefit from using these additives. Mainly, vehicles with high mileage which are constantly being used to tow heavy loads in adverse weather conditions. Heat and wear are the enemies of a transmission. Vehicles which are involved in racing or towing heavy loads are hard on transmissions. They often generate excessive heat. While transmissions have built-in systems to mitigate some of this heat and strain these activities cause, the transmissions in vehicles which are under a great deal of stress can often benefit from using automatic transmission fluid additives.

For the owners of these vehicles the minor cost of additives makes using them a no brainer. Hence, there seem to be instances when ATF additives can help yet even in those situations, however, it is essential to get the right ATF additive.

So, the next time someone tells you they have a miraculous transmission additive for sale you’ll know better.

If you’re experiencing any sort of transmission problem, please contact your local Mister Transmission and book an appointment for our FREE 21-Point Multi-Check Inspection.

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Myths About Stick Shifters

Manual transmissions are still a popular choice today as they do offer many benefits. Here we challenge some stick shift myths which are based on outdated information.

Though most new vehicles sold today come with automatic transmissions, there are people who tout stick-shift manual transmissions as being a much better option. However, some of the benefits they cite are actually stick-shift myths and are based on outdated information.

To help set the record straight, below are five common stick-shift myths, along with the truth behind each.

Myth #1: Stick shifts always get better fuel economy.

In the past it was pretty much a given that vehicles with manual transmissions would be more fuel-efficient than their automatic counterparts, but advancements in automatic transmission technology have closed that gap. It’s true that some vehicles get better mileage with a manual transmission, but the difference is usually quite small. In some of today’s models, the automatic transmission is becoming more advanced and gaining additional gears, so they are often now overtaking manuals in terms of fuel economy.

Myth #2: Stick shifts are always cheaper to buy.

Again, this is only true part of the time. In some cases, the manual version of a car will indeed cost less. But the current trend is toward pricing both manual and automatic versions of a car exactly the same.
Furthermore, you can’t always get the car you want with a manual transmission.

Myth #3: Stick shifts save on repair costs.

It’s true that replacing a manual transmission is usually cheaper than replacing an automatic. However, many automatic transmissions will never need to be replaced. With a stick shift, you’re likely to replace the clutch at least once or twice over the life of the car, which means your long-term maintenance costs may be higher.

Myth #4: Myth #4:Stick shifts are a must for sports cars.

Though manual transmissions are more common on sports cars, there will also often be the option of getting an automatic. And it’s becoming more common for some sports models to only come with automatic transmissions or to be equipped with clutchless paddle shifters.

Myth #5: Stick shifts work better for towing or other heavy-duty work. 

Actually, one could argue that stick shifts are worse for hauling loads. The increased weight increases the amount of wear on the clutch, whereas an automatic has no clutch to wear out. And the automatic transmissions on many full-size trucks or SUVs come with a towing package that can better handle the loads.

Stick Shift Realities:

When the argument in favor of the stick shift is based on how much fun it is, it’s undeniable. Stick-shift savvy also comes in handy if you’re a passenger in a manual-transmission car and the driver is incapacitated in some way. And it’s helpful if you’re stuck somewhere and the only car available is one with a stick.

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