1. How does a cooler actually function with the transmission and engine?
Heated fluid generated by the transmission, engine or power steering pump flows to the cooler. The air moving
over the fins of the cooler cools the fluid, which is then routed back to the transmission, engine or power
steering pump in a continuous loop through the return line.
2. How do you attach the transmission cooler in front of the radiator or air conditioning condensor?
The installer may choose from several options for mounting the cooler. Normally the installer uses the included
plastic rods, pads and fasteners, such as part # D13001, to install the cooler. The plastic rods are run through the
transmission cooler and through the OEM radiator or air conditioning condensor and secured with the fastener.
Another option is to use the rigid mount kit, such as part # D13002, to mount the cooler if there are mounting
points where the cooler will be placed. Third, if the mechanic is installing one of the stacked-plate coolers with
mounting tabs built into the cooler housing, then a bracket kit such as part # D50020 could be used.
3. What is the difference between the tube-and-fin cooler, the plate-and-fin cooler and the
The main difference is in the ability to cool the fluid. The tube-and-fin style has a tube that carries the transmission fluid through the cooler. It is also distinguished by its turbulators,
which agitate the fluid to get more of it to contact the aluminum in the tube. Aluminum fins are attached to the
outside of the tube and, since aluminum dissipates heat quickly, the heat from the fluid is absorbed by the
aluminum, moves out to the fins, and is then carried away from the cooler by the air flowing through the fins on
the outside of the cooler. This style of cooler works well but is the least efficient type of cooler that we carry.
Plate-and-fin coolers work on the same principle as the tube-and-fin-style coolers but are more efficient. Plate-
and-fin coolers force fluid through much smaller plates that, like the tube-and fin cooler, cause turbulation
(or agitation) of the fluid. But fluid in the plate-and-fin style is cooled better before leaving the cooler because
the smaller, flatter plates allow more fluid to contact the aluminum surface inside the cooler.
Stacked-plate coolers are the most efficient coolers. They have the same design as the plate-and-fin style, but
they have high-flow turbulators for heavy-duty towing or race applications. The stacked-plate design also includes
mounting points for mounting the cooler with the # D50020 Bracket Kit . The stacked-plate design also uses
AN (Army-Navy) fittings, which are popular in high performance and racing applications where the cooler
may need to be installed and removed more frequently than in a typical towing setup.
4. If there are 3 coolers all listed for the same weight, how do you know which one is best?
The first consideration would be the size of the cooler. Generally speaking, the larger the cooler, the better the
cooling performance will be. If there are similarly sized tube-and-fin coolers and plate-and-fin coolers, then the
plate-and-fin cooler will perform better even if it is slightly smaller. The second consideration is the mounting
location. If you mount the transmission cooler behind the radiator or between the radiator and air conditioning
condenser, a more efficient cooler is required to provide the most efficient cooling.
5. Why are coolers rated by Class?
Because we are in the towing industry, our customers are used to seeing Class ratings on their trailer hitches, so
this is an easy way to alert the customer as to which cooler is the most efficient for their towing needs. Therefore
we use the Class rating to let customers know that if they have a Class II hitch on their vehicle, then a Class II cooler
should be sufficient, but they can always use a larger cooler for more cooling if they like.
6. Shouldn't I get the one rated for the highest weight capacity? Why or why not?
The general rule is that transmission fluid cannot be cooled too much, so using the largest cooler that will fit is
a good idea, especially if you are towing. The only reason not to add the largest cooler possible would be if you
live in a very cold climate where temperatures are commonly below 0 degrees and you have a transmission cooler
installed. This would warrant warming the engine for a few minutes. Most people warm the engine in these cold
conditions anyway, so size is not a factor.
7. Will this mess up my factory transmission?
No. As long as it is properly installed, a transmission cooler will not affect a factory transmission. It is a flow-through device and does not affect any internal components of the transmission. A transmission cooler will
just help to prolong the life of the transmission by keeping the fluid cooler. Transmission fluid cannot be
cooled too much, so the addition of a cooler is a good idea, especially if you are towing.
8. Does the transmission cooler do anything if you are not towing?
Yes. The transmission cooler is a flow-through device and operates anytime the engine is running.
The fluid will flow from the transmission to the OEM cooler and then to the aftermarket cooler; and finally, the
cooled fluid flows back to the transmission in a continuous loop.
9. If the transmission cooler is a custom fit why do I need to measure?
The cooler itself is not the custom-fit part. We have transmission coolers in the fitguide because some vehicles,
mostly GM, Ford and Chrysler/Dodge, can usecustom fittings to make installation of the transmission cooler
easier and faster.
10. Do most vehicles have custom fittings available?
No. For most vehicles you will use an Insta-dapt fitting a that is included with the transmission cooler and that
connects directly to the OEM transmission cooler. Then the rubber hose going to the aftermarket transmission
cooler is clamped to the fitting, and the hose coming from it is slipped over the original line and clamped. Or,
the Insta-dapt is installed in-line between an OEM hose and the transmission cooler hose.
In addition, some vehicles will require that you cut and flare the OEM steel or aluminum transmission return line
and then clamp the transmission cooler hoses directly to the two ends of the cut line. Note: Many installers prefer
this type of installation because they already have the cutting and flaring tools and no extra fittings are needed.
For more information, see our transmission cooler installation video.
11. How do I install a transmission cooler when special fittings are available?
Special fittings are designed to make it easier and faster to install a transmission cooler. Most vehicles for which
hoses going to and coming from the aftermarket transmission cooler in-line with the transmission's return line
and the OEM transmission cooler.
12. How do you know if you need special fittings?
Our year-make-model fitguide will list the special fittings needed for a specific vehicle if they are available from our
supplier. This is why transmission coolers are listed in the fit guide on our website.
13. What is a hose barb?
A hose barb is the part of a fitting that the rubber hose slides over, as on part #D98200. The hose barb is then
secured with a hose clamp. Often the transmission cooler will have hose barb fittings for connecting the rubber
hoses to it.
14. What does NPT mean?
NPT stands for National Pipe Thread, which is a standard for threaded fittings in the plumbing industry. Much like
AN(Army-Navy) fitting, it is a way of identifying the type and size of fittings needed for an installation application.
15. Can all coolers be used on any vehicle out there or are the ones listed in the fit guide search only for that
year, make and model?
A transmission cooler is a flow-through device and is not designed specifically for any particular year, make and
model. Any cooler can be used on any vehicle with an automatic transmission, provided that it will fit in the
location where the customer wants to install it. Year-make-model fittings are available for some vehicles to make it
easier to install the coolers. You can use the fitguide to determine whether or not a vehicle can use a custom
16. Just because the fitguide does not list a transmission cooler for a vehicle can someone still put one on?
Yes. The installer will need to determine how to install the cooler on the vehicle. Any of the installation procedures
explained previously can be used. We do not list a transmission cooler if we do not have information from the
transmission cooler manufacturer or when the vehicle manufacturer does not recommend installing a transmission
cooler on the vehicle.
17. Can I use an oil cooler, power steering cooler and transmission cooler all together?
Yes. You can install all three on the vehicle. You would need three separate coolers and have the space needed to
install each one. We carry some dual-function coolers (see part #D15321), that can be used for two of these
functions. These are basically two separate coolers in one with an inlet and outlet for two different fluids.
18. Do the coolers mount in the same location as other items, like power steering coolers and engine oil coolers?
Yes. If you are installing more than one cooler you will need to carefully consider the fit. As long as there is enough
room, it is possible to install all three coolers.
19. I have lines running from my transmission to my radiator. How does the transmission cooler actually install to
Transmission coolers do not attach to the radiator. They attach in-line with the transmission fluid return line. It is
common for an OEM transmission cooler to be built into the radiator tank to be cooled by the coolant in the
20. Does the transmission cooler need to be installed with the hose fitting in any certain position?
No. The cooler can be installed with the hose fittings in any position that will make the installation easier or look
more professional on the vehicle. It does not matter which fitting on the cooler is used for the inlet or outlet.
21. Do I need an oil cooler also?
Oil coolers are optional. Many people choose an oil cooler when their towing application is heavy duty, such as
towing a fifth-wheel trailer or gooseneck trailer. The oil cooler is based on the same flow-through principle as
the transmission cooler. It is installed in-line with the vehicle's oil delivery system, and then the oil pump pushes
oil through the cooler and back into the engine. If a vehicle manufacturer recommends an oil cooler for towing,
then it would be needed for that vehicle. The customer should check the vehicle owner's manual.