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Performance Transmission Coolers Keep Your Temperature Down When Trailering

Automatic transmissions piggyback onto engine radiators for fluid cooling. Here, we discuss auxiliary coolers dedicated to trans fluid only – a must for heavy-duty use or towing.

Recent data from USA Today states that only 6.5% of new vehicles sold in the U.S. are equipped with manual transmissions. The reverse of that means 93.5% of all new cars and light trucks are sold with automatic transmissions. Therefore, the odds are that your ride has an automatic. A less-known fact about those transmissions is that they all have built-in oil coolers, and the vehicle's radiator does double duty, shedding heat from both the engine coolant and the transmission fluid (ATF, or "automatic transmission fluid").

Transmission

In spite of the factory coolers, today's driving puts more strain (and higher temperatures) than ever on your vehicle. Transmission industry experts have pointed out that high ATF temperatures mean shorter transmission life spans. There is data from knowledgeable sources to suggest that 9 out of every 10 automatic transmissions which fail do so because of overheating. It's also been stated that every temperature drop of 20 degrees F can effectively double transmission component life. Put into more practical terms, ATF which runs at 260 degrees F can cause component failure in as little as 5,000 miles. Reducing that ATF temperature to 175 degrees F will likely give you 100,000 miles or more of service from your tranny. So cooler is better for transmission life.

Royal Purple
Royal Purple brand Automatic Transmission Fluid is high-performance ATF, which is the perfect complement to your auxiliary transmission oil cooler.

If you tow a trailer, adding thousands of pounds of weight behind you, you are putting additional stress on every mechanical component of your car or truck. Your transmission is taking things especially hard, as trailering will greatly increase transmission operating temperatures. Yet you can do something about it. Auxiliary transmission oil coolers are available which are affordable and easy to install. They will lower the temperature of the ATF, allowing you to enjoy your trailering experience without subjecting you to undue worry about whether the tow vehicle will make it home or not.

"Car overheating" is not always the radiator! Your transmission can also overheat and cause a breakdown.
Overheating is the number one enemy of the transmission causing most problems of this system.

These auxiliary coolers are designed to operate alongside your existing tranny coolers. They are usually installed in front of the radiator for maximum air flow. If space is at a premium, there are special models with their own fans which can be installed remotely. Let's check out several of the manufacturers whose products are featured on our website.

Hayden

Hayden Automotive is a brand that specializes in automotive cooling, so they know their stuff when it comes to transmission coolers. Their entry level, most cost-effective line of transmission coolers is called "Ultra Cool". These are available in light duty, medium duty, and heavy duty applications (in different sizes depending on specific vehicle fitment), and use a traditional tube and fin design. The cooling kits include hoses, fittings, and attachment hardware. All fittings are 3/8" push-on.

Hayden's Ultra Cool Transmission Cooler Kit.
The Hayden High-Performance Transmission Oil Cooler.

Hayden's "High Performance" coolers also use a tube and fin design, and the aluminum construction keeps weight down while maintaining cooling efficiency. These kits also include the necessary installation hardware. There are three different sized coolers: the 512 model is designed for vehicles towing up to 2,500 lb.; the 514 version if you are towing up to 5,000 lb.; and the heavy-duty 516 cooler for vehicles towing up to 10,000 lb.

The Hayden Rapid Cool Transmission Cooler Kit.
The Hayden "Dawg" remote-mountable transmission oil cooler, with built-in cooling fan.

The Hayden "Rapid Cool" transmission coolers use a plate and fin design, which is about a third more efficient than the traditional tube and fin set-up. Rapid Cool models are available in four sizes: 6" by 11" for subcompact and compact vehicles; 7.5" by 11" if you're towing up to 2,500 lb.; 9.5" by 11" for trailer weights up to 5,000 lb.; and 11 5/8" by 11" if you're pulling up to 10,000 lb. All models come standard with push-on fittings. The 7.5" x 11" and 11 5/8" x 11" models have the option of threaded fittings.

All the above Hayden model transmission coolers are intended to be mounted in front of your vehicle's radiator or A/C condenser for maximum air flow. You want the passing air to take the heat out of the ATF before it's circulated around again back into the transmission. The cooling kits include instructions on how to make the installation.

If space is at a premium at the front of your ride, don't give up! Instead, check out the Hayden "Dawg" remote coolers. All these units feature an integrated cooling fan attached to the cooler itself. The pre-assembled fan means you have additional freedom to mount the Dawg cooler in a more remote location, and you are not tied to relying on the ram air effect you get in front of the radiator. The Dawg remote coolers are available in both Rapid Cool kits (with push-on fittings) and Ultra Cool kits (with threaded fittings).

Flex-a-Lite

Flex-A-Lite, a U.S. based family business that has been around for over 50 years, has made a name for itself with its electric cooling fans. It stands to reason that a perfectly complementary product would be oil coolers. And so it is: their TransLife transmission oil coolers will get your ATF temps under control and prolong the inner workings of that automatic gearbox.

The great thing about the TransLife line of products is that since they are all universal products, you simply find the overall dimensions that will fit, combined with the GVW (Gross Vehicle Weight) of your combo tow vehicle/loaded trailer, and you'll have the unit you need. Remember that all these units will need to be mounted in front of the car's or truck's radiator/AC condenser.

The Flex-A-Lite TransLife model 4112 transmission oil cooler.
The Flex-A-Lite model 4120 TransLife oil cooler.

For example, the 4112 model measures a compact 5" by 15" and can handle up to 12,000 GVW (ALL TransLife coolers are only 3/4" deep!). So if it's light-duty pulling you're doing, then don't spend more than you need.

If you can fit something a little larger, take a look at the 4116 (7.5" by 12", 16,000 lb. GVW), 4118 (7.5" by 15", 18,000 lb. GVW) or the 4120 (7.5" by 20", 20,000 lb. GVW).

All Flex-A-Lite TransLife transmission oil coolers are available with your choice of barbed fittings or AN fittings.

B & M Transmission

B & M Transmission has a world-wide reputation for manufacturing some of the best high-performance and racing transmissions and tranny components. It would make sense that transmission coolers would be an integral part of their performance lineup.

There are two product lines to choose from when considering a transmission oil cooler from B&M. Their "Supercooler" line uses aluminum stacked plate style core design. Oven brazed construction helps these units stand up to rocks and other road debris. All these coolers use NPT fittings, and are selected either by size or by BTU (British Thermal Units, a way of measuring cooling capacity). The ones rated by BTU are complete kits. While most of these units are finished in black, there are several sizes in an optional polished finish. The Supercooler lineup is designed to be mounted in front of a radiator for the ram air effect.

The B&M Supercooler in black.
The B&M polished Supercooler.

If choosing a unit by size, measure your available space, then consider a cooler in small (7.25" by 11.25"), medium (10" by 11.5"), or large (11.5" by 13"). All of these units are finished in black. Polished aluminum choices come in two sizes: either 4.5" by 11.25" or 8.5" by 11".

B&M oil cooler kits are rated by cooling capacity (the larger the number, the greater), and include one with a 9800 BTU rating (5.75" by 11"); a 13,000 BTU rating (8.5" by 11.25") ; and a 14,400 BTU rating (5.75" by 11").

B&M 14 400
The B&M 14,400 BTU transmission oil cooler kit.

The second model from B&M are their "Hi Tek" oil coolers. They feature built-in fans, so these are for use specifically when remote mounting is a choice, or is the only choice. NPT fittings are again employed, and the all-aluminum assemblies include built-in mounting brackets for ease of installation.

B&M hi Tek
The B&M "Hi Tek" oil cooler with built-in fan for remote mounting.

There are two sizes: the medium size measures 10" by 7.5" and can handle 350 CFM (cubic feet per minute) of air flow. The large size is 9" by 13.5" and 590 CFM of air can travel through it.

With this many choices in the field of transmission oil coolers, you are certain to find a fitment which will work with your specific year, make, and model vehicle. Of course, our website is set up to help guide you to the best choice. If you are towing, whether for business or for pleasure, and plan to keep your tow vehicle going for "the long haul", consider a transmission oil cooler for your rig. It's an investment that is guaranteed to pay you back many times over its initial purchase price.

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