transmission
Importance of checking transmission on a used car:
Transmission is one of the
key elements that make the car go. It's an integral part of drive train,
attached to the engine, it has several gears that allow the car to drive at
different speeds. Quite often many used cars that are rather old develop transmission
problems. Transmissions are costly to repair (at least 1500$ for a complete
overhaul) and can break suddenly without any signs of trouble. Transmission is a
fragile part of drive train and if it has been abused, it is virtually
guaranteed to have problems in the long run. It is possible to destroy a brand
new transmission within a few hours of extensive abuse.
Types of transmissions and their
advantages/disadvantages:
Automatic transmission
- most commonly found on cars in USA, it basically put responsibility for
switching gears on internal computer, rather than on the driver. Automatic
transmission are rather fragile (more so than manual transmissions) and require
more care than manual transmissions. Automatic transmission's advantage is ease
of driving, especially in stop-and-go traffic. Disadvantages are: it requires
more maintenance than manual transmission, it is more likely to break suddenly
than manual transmission, it is less fuel efficient and generally has less gears
than manual transmission. Overall, it is designed for everyday cruising and
people that would like to minimize their input into driving the car.
Manual transmission
- less common in USA, but still quite popular. Driver is responsible for
shifting gears and it can take quite some time to learn how to drive one.
Usually manual transmission cars are more fun to drive, since they give more
overall control to the driver. Manual transmissions generally are more reliable
than automatic transmissions, due to their simple design and get better gas
mileage. On the other hand, they take more effort to drive and can be somewhat
of a hassle in stop-and-go traffic. For some people it is challenging to drive
manual transmission, because it requires quite a bit of skill and practice to
achieve perfection.
Variable-rate transmission
- it has variable gear ratios that always provides optimum output. It is not
very common on cars and the technology is relatively new. You can find it on
some hybrid cars, such as Toyota Prius.
How to check if transmission has
any potential problems?
First thing to check for
are leaks. You should check for leaks before and after the test drive. Most
common place where transmissions leak are where they connect to the engine. Look
around that area and see if you can spot any leakage.
Automatic transmission
- first thing first, go on test drive to test the transmission. It has to be hot
to get accurate transmission fluid reading. When you switch the shift lever from
Park to Drive it should engage smoothly, and make the car creep forward
slightly. If it kicks really hard or takes long time to engage, then the
transmission is worn. Go through all gears and see how it engages. It should do
so smoothly, quickly and without any jerking or loud thumping. Go out for a test
drive and feel how it shifts. Shifts should be smooth, barely noticeable (if at
all). Any roughness is an indicator of transmission wear. Try to check
transmission downshift by flooring the car at random times. It shouldn't take
more than a couple of seconds for it to downshift to a lower gear. Also try the
following trick: floor the car so it goes up to around 30mph, then suddenly
brake to around 5mph and then floor it again. This trick is a very good trick
for testing overall condition of transmission. If you feel any thumps,
irregularities or feel excessive lag or slipping, then the transmission is worn.
If at random times you can hear the engine revving up, but car not moving along with
RPM increase, the transmission is slipping (do not buy the car)
Automatic transmission
should operate equally well when it's hot and when it's cold. It might take a
split second longer to engage gears when it's cold, but the roughness should
completely go away after it warms up. If it doesn't, then the transmission is
worn and might soon require overhaul.
After transmission gets
hot and you come back from a test drive check the fluid level. Some cars require
that the car be still with an engine on, some require that the engine be off.
Look into car's manual and see that the procedure is for that specific car. The
fluid should be bright pink/red/sight light brownish color and should smell like
new fluid. If it's dark brown and smells burnt, the transmission will require
overhaul shortly and you're better off avoid such car.
Manual transmission
- manual transmissions are rather easy to check. The most important component is
clutch. Before checking the fluid, take the car out for a test drive. Engage all
gears in sequence and see if any gears grind or a hard to engage. This might
indicate that transmission is worn. To check for clutch slippage - stop the car
and engage 5-th gear and slowly depress the clutch as you press the accelerator
slowly. The engine should stall and if it doesn't even after you completely
depressed the clutch, then this indicates clutch slippage and it will require
replacement shortly. When test driving the car, feel how the clutch engages. If
it's rough or there is any vibrations, this might indicate warped flywheel.
Manual transmission should be very smooth when you engage and disengage the
clutch and shifting should be rather effortless. After test drive check the
fluid level. It is rather hard to tell the condition of the manual transmission
based on fluid condition. If you notice any roughness or vibrations when
switching gears or engaging the clutch, it is likely that the manual transmission
and/or clutch are worn.
Conclusion:
Going through trouble of
really evaluating the transmission can save you thousands of dollars in
potential repairs. Usually transmissions give you some sort of wear indicators
that we discussed here. By knowing what to look at and how to test it, you will
gain an ability to tell if the transmission is worn.
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