Frequently Asked
Questions...
The UK's Leading Independent
Automatic Gearbox Specialists. Repairs Rebuilds and Reconditioned Gearboxes.
Contents:
Is my transmission really
broken?
To answer this question, you should check the
oil level. Also it would be good to remove the oil pan as well as the filter -
If they are dirty then you have problems.
If the transmission oil is still in good
condition, that means red (or yellow in some transmissions) and not burnt, and
if there are no pieces of dirt in the oil, you have a realistic chance that your
transmission is not damaged at all or that it is not very badly damaged. In that
case it would make sense to make an appointment with us to check if there is an
external control problem.
With mechanic-hydraulic transmissions the cause
for the defect can be a bad modulator, broken TV cable, a stick governor, a
sticking or bad valve body or an internal leakage.
With the later, electronically controlled
transmissions there can be an external error for example, a bad throttle
position sensor, a defective external shifter or wiring fault that is
responsible for the defect.
If the vehicle moves neither forward nor
backward it might be the torque converter that could be damaged.
But in cases like that there is a good chance
for you to save money.
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Does my transmission have to
be removed?
You are able to answer this question relatively
easily yourself by firstly checking the colour and smell of your automatic
transmission. If the oil is dark brown or black or smells burnt then your
transmission has to be removed.
If that is not the case, you should remove the
oil pan and check if there are any metal pieces in the pan. If there is a lot of
metal contamination, or if there are even bigger metal parts in the pan or on
the magnet, there is such a bad mechanical defect that the transmission would
need to be removed.
If there is really bad pollution and/or large
metal parts, your transmission needs a major overhaul as soon as possible to
remove all the dirt.. If this is not the case you are welcome to consult our
technical director Eddie Rose for further advice.
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What is the difference between a repair and a major overhaul?
During a major overhaul all the retailed parts
are changed and it doesn’t matter if they are broken or not. The overhaul has a
fixed price if there is no damage on the valve body or transmission housing. You
receive a 12 month warranty on the whole transmission.
During a repair only the obviously defective
parts are removed. A repair depends on the effort made. The minimum costs are
usually between <please call us> plus VAT depending on the type of transmission.
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Are there any opportunities to make my transmission stronger?
Depending on your transmission and
manufacturer, there are deferent opportunities to make your transmission
stronger. You should get advice from an expert before every strengthening of
your transmission so that you will get a strengthening that matches your
requirements.
Especially for most American transmissions
there are a lot of improvements available, for example high performance
clutches, brake bands, high performance servo pistons, aluminium oil pans and a
lot more. But even strengthening that are universal are possible, such as oil
coolers, temperature sensor and gauge and performance improving transmission oil
additives etc.
There is no major rule so please talk to our
expert about it.
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Why do automatic
transmissions vary so much in price?
Because there is no major regulation for
rebuilding an automatic transmission there are a lot of totally different
efforts made that are hardly comparable.
There are a couple of questions to ask you to
judge the efforts made.
Did you get enough advice before placing
your order?
Will the transmission be repaired or
generally rebuilt?
Will the transmission be fully cleaned both
inside and out?
Will the transmission be equipped with a
rebuilt torque converter?
Are the planetary gears and all the other
interior parts included in the price, or do you have to pay separately for
damaged hard parts?
Will the transmission be filled with oil
and be tested on a dyno test bench?
Does the transmission carry a warranty?
Is there a mileage limit?
Does the warranty include the whole
transmission or only damaged parts?
What if the told efforts from above are not
included in the price?
Is there a collection and delivery service?
Do you know anyone else who has bought from
the supplier and who is able to recommend it?
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What is a
Lockup?
A lockup is one more clutch that is located in
the torque converter and that starts working if you are reaching high amounts of
revolutions or mostly it starts working when you are in third gear. That is
important to get a closed connection from the engine to the transmission. Like
that you are able to prevent the loss of RPM’s and the resulting use of too much
fuel.
As long as the lockup doesn’t work, there is no
stable connection between engine and transmission. The power is transferred
through two paddle wheels by the oil as a medium. One paddle wheel is driven by
the engine and the second by the oil stream.
The two paddles are located on the inside of
the torque converter. They are only connected by the medium oil and that is why
there are different amounts of revolutions of the engine and the transmission.
The lockup overrides when there is a higher
amount of revolutions. If there is only a small difference between the input and
output revolutions that means a clutch in the torque converter is closed so that
there is a fixed and stable connection.
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Why does a Torque converter have to be replaced during a major overhaul
even if it is still working?
Broken automatic transmissions are almost
always badly polluted. Those pieces of dirt, like metal pieces or burnt friction
of the clutch are in the torque converter too.
If you use an old torque converter when
rebuilding a transmission, all the dirt will get through the oil circle in the
torque converter back into the transmission, causing another defect.
To flush the torque converter is not enough to
get all the dirt from the converter. You cannot see inside a torque converter
with a lockup and that is a problem because you don’t know if the friction
material of the lockup has already been damaged.
Only transmissions that are relatively clean
can be repaired. In that case of torque converter may be re-usable to save
money.
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Why does the oil cooler have to be removed or at least cleaned out when you
change or re-build a transmission?
Small metal parts or burned friction material
get through the oil circle even in the cooler.
When the transmission is rebuilt and the oil
cooler is not completely clean the small pieces of dirt slowly get through the
oil circle back into the transmission.
In some cases the oil cooler is so badly
polluted that there is not enough or even no oil. A sufficient cooling of the
transmission is not possible anymore. In that case, or if there are big metal
parts all over the transmission, the oil cooler has to be removed otherwise the
rebuilt transmission will overheat within a short time and will get damaged
again.
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What is the inline filter?
Even if the oil cooler is cleaned thoroughly it
is not always possible to get all the small pieces of dirt from the cooler.
That filter is installed in the return line
in-between the oil cooler and the automatic transmission.
The filter consists of three components, a very
thorough filter, a magnetic ring to catch all the little metal part and a bypass
valve that opens if the filter is full. That ensures a constant oil cooler flow
and guarantees that cooling of the transmission oil.
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This is just a guide to the most frequently asked questions about automatic
transmission. If you have any specific questions then please call us on 01623
624741 or send us an email via the contact page.
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