The transmission in a car delivers the proper amount of power generated by the engine to the wheels, much the way the gear shifter on a bicycle works.
Imagine getting on your bicycle and attempting to start from a standstill in the highest gear on the bike. It would be nearly impossible to move. You don’t have enough power in your legs to push the bicycle forward against so much resistance. Now imagine the flipside: racing down a hill in first gear. You would burn yourself out trying to pedal fast enough to have any impact.
This is similar to driving a car without a transmission.
The transmission is the gear shifter, changing gears to adjust the amount of power to turn the wheels. In a manual transmission, the driver makes the decision about when to shift and instructs the transmission to do so by depressing the clutch to disengage the gears and shifting from one gear to another. In an automatic transmission, a computer senses the vehicle’s power needs and changes gears itself.
For a long time, manual transmissions were more efficient because they used less fuel than automatic transmissions by changing gears indirectly. Since the use of computers, automatic transmissions have become so sophisticated that they are now as efficient as manuals and provide a smoother ride. There isn’t much need for manual transmissions anymore.
Absent a transmission, it would be almost impossible to move the car from a starting position. If you did manage to get the car moving, the engine would burn itself out once gears started turning faster and the car picked up speed. In other words, the transmission is essential to the operation of an automobile.
The Importance of Transmission Fluid
Transmission fluid lubricates, cleans, cools, and protects transmission components, just as motor oil does for the engine. But don’t confuse transmission fluid and motor oil: they are two different things that work differently and are not interchangeable.
Losing transmission fluid has the same impact on the transmission that losing motor oil has on the engine. Without lubrication, the gears can grind to a halt. The gaskets can crack. The transmission can burn up and cease functioning. Danger, Will Robinson! Check your transmission fluid levels and address any leaks or low levels before the transmission sustains damage.
Improved transmission fluid formulas are good for 150,000 miles, triple the distance you could drive in years past before changing the fluid.
Transmission fluid can be red or reddish-brown and is sometimes confused with power steering fluid, in part because of their similar color and in part because they leak from the same part of the engine. The difference is that transmission fluid feels slick and smells like gasoline.
If you have a transmission fluid leak, particularly if you notice the engine having difficulty changing gears, an easy solution is to pour a bottle of BlueDevil Transmission Sealer into the transmission. It permanently seals transmission fluid leaks by restoring dried, cracked and shrunken rubber seals and gaskets. Follow the directions on the bottle for optimum results.
Transmission Fluid vs. Motor Oil
Transmission fluid and motor oil do similar things for different parts of the car, but they are not the same. Both transmission fluid and motor oil are composed of refined crude oil and additives. The main purpose of automatic transmission fluid is to serve as part of a hydraulic system in which the fluid is compressed to move the gears. It also lubricates, cleans and cools the other parts of the transmission. Manual transmission fluid doesn’t need to be compressed, so it acts more like motor oil to lubricate, clean, and cool.
Engine oil is amber colored when new and turns brown when it is used. Automatic transmission fluid is dark red while manual transmission fluid is generally dark green. They all have similar viscosity, though transmission fluid will usually be a bit thicker, particularly out of the bottle.
If you accidentally pour engine oil in the transmission, the oil must be flushed out as soon as possible or it could damage the transmission. That small mistake could result in a $5,000 transmission overhaul. (The reverse is also true: pouring transmission fluid into the engine could cause grievous damage to the engine. Drain the fluid immediately.)
The symptoms of motor oil in the transmission include grinding gears, gear slippage or difficulty operating in gear, a burning smell coming from the transmission and excessive noise from the transmission. Eventually the Check Engine light will come on. By that time, some of the damage is already done.
How Much Does a Transmission Weigh?
For the most part, the driver doesn’t need to know how much their transmission weighs. They might be more interested in its cost – $2,000 or more rebuilt, $4,000 and up new – particularly if they must replace or rebuild the transmission. If you plan to lift or move the transmission, then it is helpful to know how much it weighs. That, of course, varies by make and model of car. One thing all car transmissions have in common: they are heavy.
Most transmissions weigh between 100 and 400 pounds, with an average transmission tipping the scales at 226 pounds. Truck transmissions tend to be heavier, as are automatics, because of their complexity. An automatic transmission weighs 50-75 pounds more than a comparable manual. About half that difference is due to the cast iron case surrounding automatic transmissions.
The transmission in a front-wheel drive Honda Civic is closer to 100 pounds while a Ford F-150 with an automatic transmission comes in at 215 pounds.
Two or three DIY mechanics could lift the Civic’s transmission out of the car, but you need a lift to get the truck transmission free.
Here are a few other transmission weights:
Ford Performance Super Duty Truck with manual transmission – 87 pounds
Chevy Cobalt with automatic transmission – 102 pounds
Toyota Corolla with automatic transmission – 169 pounds
Dodge Ram truck with automatic transmission 238 pounds.
Ford Trans with automatic transmission – 363 pounds
These weights are important primarily if you’re removing the transmission and replacing it with a new or rebuilt version. This is a highly dreaded scenario. Let’s examine what you should expect after a rebuild.
Problems After a Transmission Rebuild
Let’s say you did pour engine oil into your gearbox and didn’t realize until the transmission had already seized up. You brought your car to a mechanic who just shook his head and spoke the dreaded word: “rebuild.”
After you’ve emptied your 401(k) to get a replacement transmission, it should ride smoothly and change gears effortlessly, as before, but possibly not right away. You should be prepared for some predictable issues in the wake of a rebuild.
For the first 500 miles or so, it is a good idea to avoid stop-and-go driving. This is a strain on the transmission and could cause problems for a transmission that needs to be broken in. It is also important to avoid using the vehicle to tow other things like boat and ATV trailers. This will allow the various transmission elements, like the clutches, flex plates, mounts and torque converter to settle into place.
It is possible the shifting may feel different with the refashioned transmission, particularly at first, before the lubricating oil has seeped into all the crevices. The shifting may feel clunkier and offer more resistance. That is normal – for a while.
One positive expectation you should have for your new transmission is its lifespan. A properly rebuilt transmission should last about as long as a new transmission – about 200,000 miles. That assumes it was rebuilt using quality parts and you drive it sensibly.
Do Transmission Fluid Additives Help?
Visit your friendly neighborhood auto parts store and you will find shelves full of transmission fluid additives claiming to help the transmission fluid lubricate and clean the transmission and extend its life. Over time and heavy use, particularly if the car is being towed or is towing or hauling cargo, the fluid begins to break down and lose its original lubricating, cleaning and cooling properties. Additives are designed to reduce friction and extend heat resistance.
These additives have been thoroughly tested by independent parties and generally found to be useful in the short-term. If your goal is to keep your car on the road through the winter before flushing the transmission fluid, a quality transmission fluid additive can be helpful. They may also provide a benefit to vehicles under constant strain from towing, hauling and racing.
In the long run, these additives break down and provide little-to-no protection, and can even harm the transmission. Ordinary transmission fluid is specially formulated to contain all the additives it needs for optimal functioning. Research has shown that further additives can actually degrade the fluid in the transmission and shorten the transmission’s life.
BlueDevil Products can be found on Amazon.com or at AutoZone, Advance Auto Parts, O’Reilly Auto Parts, NAPA, and other major auto parts retailers.
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