Q: What is the difference
between a transmission fluid and filter change and a flush?
a transmission fluid and filter change only the fluid that is in the
pan is drained and replaced with fresh fluid (approximately 4 to 5
quarts). With a complete flush, all the fluid is drained and/or flushed
from the transmission, torque converter and cooler lines and replaced
with fresh fluid (approximately 9 to 13 quarts). Visit our DIY Center
to learn how to do a filter
and fluid change or a transmission flush yourself
to save money.
A transmission flush is not recommended for vehicles with high mileage
in which the transmission has not been regularly serviced. If you are
unsure as to whether the transmission has been regularly serviced - a
fluid and filter change is typically recommended over a fluid
transmission failed - is it better to have it rebuilt or purchase a
used or remanufactured transmission?
short answer to this question is that rebuilding a transmission
typically costs less than purchasing a remanufactured transmission.
However, there are instances when the opposite is true. This is usually
the case when the transmission to be rebuilt has suffered extensive
internal damage resulting in higher parts and labor costs than what a
normal rebuild would cost. In such instances, the rebuild cost can
exceed the cost for a remanufactured transmission. For older vehicles
with a value of less than $3,000, a used transmission might be the best
Q: What ATF (Automatic Transmission
Fluid) should I use in my vehicle?
if your vehicle is still under the manufacturer's warranty, you must
use the ATF that is described in your Owner's Manual in order to keep
the warranty intact. This is true even though there are
other fluid options available. For older vehicles
vehicles that are no longer covered by a warranty, you can follow the
strict recommendations of the vehicle manufacturer or when doing so is
either cost prohibitive or inconvenient, you can consider one of the
aftermarket fluids of the same type. Learn more about
automatic transmission fluids and which aftermarket fluid can be
substituted for the manufacturer's brand.
Do aftermarket extended
auto warranties adequately cover the automatic transmission and
warranties typically cover the vehicle's powertrain, which the
transmission is one of the powertrain's major components.
extended warranty companies specifically offer a Powertrain Warranty,
which covers the engine, transmission and the other components of the
powertrain. However, the only way to be certain is to read
warranty coverage and agreement carefully before signing up.
How do I know for certain
my transmission needs to be rebuilt?
only sure way to know if your transmission needs rebuilding is to have
a professional diagnostics done at a reputable transmission repair shop
the dealership where you purchased the vehicle.
The most common signs that an
automatic transmission needs to be rebuilt are:
Dark "Burnt Smelling" Fluid
- In some instances, if serious damage has not already occurred, a
transmission fluid change or flush may suffice in prolonging the life
of the transmission. However, very dark "burnt" fluid
means internal damage has already occurred. In these
rebuild would be necessary.
- When the automatic transmission in a high mileage vehicle begins to
slip, the most likely cause is excessively worn clutches, in which case
a rebuild is necessary. However,
some instances, particularly in low mileage vehicles, slipping may be
caused by low,
dirty and/or burnt transmission fluid or even by a faulty electrical
sensor or solenoid. Therefore, these potential causes must be
ruled out before proceeding with a rebuild.
Shifting Problems - A transmission that does not shift
at the proper times or shifts hard from one gear to the next or does
not shift at all may be worn out and in need of a rebuild.
But, these same symptoms can also be the result of an adverse fluid
condition, an open circuit in
the electrical system, a faulty shift solenoid, a bad Transmission
Control Module (TCM) or anyone of a number of other problems, which all
must be ruled out before proceeding with a rebuild.
Unusual Transmission Noise(s) - Grinding, chattering or the sound
of metal parts clanging together is a good sign the transmission is
damaged internally. With internal damage, the transmission
must be removed from the vehicle and disassembled. While it
may be possible to replace only the damaged part(s), the transmission
should be rebuilt once it is removed from the vehicle and opened
up. The only exception would be if the vehicle has low
mileage and the friction clutches and seals are in good condition.
can't I get a straight answer from the transmission shop about what it
will cost to rebuild my transmission?
if a transmission repair shop will not give you an estimate for
repairing or rebuilding your transmission then you should leave that
shop and go to a different shop. (See our list of
recommended "reputable" shops in your area).
With respect to getting a quote for a transmission rebuild, this is
normally no problem except in instances where the technician suspects
the transmission has suffered more damage internally than a standard
rebuild would cure. In these situations, the exact cost
determined until the transmission is removed from the vehicle and
disassembled. It is impossible to know which parts need to be
replaced until the transmission is disassembled. In such
instances, the transmission shop can and should be able to give you a
best and worst case quote.
you having trouble getting your transmission problem diagnosed and/or a
reasonable quote for the repair, consider calling or visiting one of
our recommended shops
in your area.
long do automatic transmissions last?
have been answering this question for the past 30-years and the answer
is always the same, which is; "We cannot say how long a particular
transmission will last but we can explain why some transmissions last
longer than others". After we finish our explanation, most
are surprised to learn that the biggest factor that determines the
service life of an automatic transmission is the vehicle owner, not the
car manufacturer. As the owner, the knowledge you possess
your your transmission and how you use that knowledge have the greatest
impact on whether your transmission fails prematurely or outlasts the
rest of the vehicle. We developed this Website to help you gain this
My transmission is not shifting
correctly - what could be the problem?
transmission fluid level can cause shift problems. Old, dirty and/or
burnt (oxidized) transmission fluid can also cause shift problems. In
other words, any adverse fluid condition can cause shift problems,
including not shifting at all. How
to properly check ATF level and condition in your automatic
A plugged transmission filter
can also cause harsh and erratic shifts, which a fluid and filter
change should resolve.
If the fluid level and the fluid
condition checks out okay, the problem might be a faulty sensor or
shift solenoid. If the cause is a sensor or solenoid (or
electrical in nature) the
Check Engine Light may illuminate or the Transmission Overdrive Light
my illuminate or flash. In either case, the next step in
determining the source of the shift problem is to have the engine
scanned (if the check engine light is illuminated) or the transmission
scanned (if the transmission overdrive light is illuminated or
While most auto parts stores offer free engine "OBD II" scans, a
special transmission scanner is needed to scan and diagnose many
automatic transmission problems. For a transmission scan, you
will need to visit a transmission shop or the dealership, as general
auto repair shops do not typically have these scanners. Need a
recommendation for a reputable transmission shop in your
area? Click here
does it mean when a transmission is "slipping"?
slip (or slipping) describes a condition in which the transmission is
not transferring the engine's power to the drive wheels as it normally
does. When a transmission is functioning properly, vehicle
up and speed increases proportionality with acceleration. In
slipping condition, vehicle pick up and speed do not respond
proportionally to increased acceleration. Unless the
causing the slipping is identified and repaired, the problem will get
worse. In extreme slipping situations, the vehicle
will not move.
causes an automatic transmission to slip?
The most common causes of
transmission slipping are;
- Low transmission
- Old and dirty
transmission oil filter
- Faulty sensor or
the check engine light come when the transmission malfunctions or has a
answer to this question is "maybe". Depending on the year,
and model of the vehicle and what problem the transmission is
experiencing, the check engine light may or may not
In other words, do not rely on the check engine light to inform you of
a transmission problem.
I take off from a dead stop, I hear and feel a thump that appears to be
coming from the area of the transmission - what could this be?
your transmission and engine are working correctly, the thump noise you
hear and feel at take off is most likely transmission, or transaxle,
mount that is worn out . It could also be a motor
This is easy to check - here is all you need to do:
You will need a helper to perform this test.
the hood and stand next to the driver's side front fender so that you
have a good view of the engine and transmission.
your helper sit in the driver's seat and start the engine.
ask your helper to depress the brake pedal firmly and move the shifter
to the Drive position.
your eye on the engine and transmission, have your helper press down on
the gas pedal and hold it there for a few seconds and then release it
all while continuing to press firmly on the brake pedal. Have
helper do this several times while you watch the movement of the engine
and transmission. If an engine or transmission mount is badly
worn or broken, the engine and/or transmission will jerk upwards or
downwards each time the throttle is increased and decreased.
you see excessive movement of the
engine/transmission you'll see the location of the worn or broken mount.