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Published Dec. 3, 2020

The minute you begin throwing power-adders on a vehicle and subject it to any sort of heavy-duty driving, the factory cooling systems have a harder time doing their job. In terms of keeping things cool, your mind automatically wanders to the radiator. But what about that automatic transmission? Automatic transmission fluid breaks down as temperature rises, and when it does, the transmission doesn’t have much time left. It doesn’t matter if you’re dashing through the quarter-mile, hauling trailers, or turning oversized tires, you want to keep that gearbox cool. Adding a transmission oil cooler is precisely how you do that. But before you run off and buy the first thing that’s available, we’d like to set you up with some pointers on what to run and why.

The Best Transmission Oil Coolers

We kick off our list with an entry from a familiar brand to those who make updates to their automatic transmissions. It should come as no surprise that a brand recognized for its aftermarket shifters, shift kits, torque converters, and so on offers a killer transmission oil cooler. There are a few things we love about this model, but we’ll start with the basics. It is a universal transmission oil cooler that measures 11 inches by 7.25 inches with a depth of 0.75 inches. These measurements and the incorporated bracketry makes it the perfect choice for many applications. Beyond that, it offers superior cooling on account of its stacked-plate design and aluminum alloy construction. Truck owners and car nuts are sure to get some use out of this design, and the middle of the road pricing drives it home for many.

There’s not much to dislike about this option. Aside from swapping out the included hose clamps and hardware, there’s no real setback.

Key Features
  • Stacked plate design
  • Aluminum alloy construction
  • Measures 11 inches x 7.25 inches x 0.75 inches
Specification
  • Brand B&M
  • Model 70268
  • Weight 3.5 pounds
PROS

Superior cooling

Reasonable pricing

Good sizing

CONS

Automatic transmission fluid only

Comes with subpar hardware

The Hayden brand is known for supplying quality transmission coolers, and its prices should be no indication that they are subpar. This particular entry measures 5 inches x 15.875 inches x 0.75 inches, which is the perfect size for compact and mid-size cars. But that doesn’t mean you can’t run it on trucks, SUVS, or other applications. It is rated to handle gross vehicle weights of up to 16,000 pounds. Further necessary details to cover are the fact that it’s a traditional tube and fin design and is ultrasonically soldered for enhanced durability. You can rest easy with the peace of mind knowing that Hayden also pressure tests these units to ensure they’re reliable. Of course, it comes with all the necessary mounting hardware, including the hose, and it doesn’t cost an arm and a leg.

A manufacturer like Hayden can’t get a design like this wrong, and there’s nothing to dislike, given the price point. If you want to get real picky, it’s not as pretty as some other options. But it doesn’t need to be pretty to work.

Key Features
  • Tube and fin design
  • Ultra-sonic soldering
  • 5 inches x 15.875 inches x 0.75 inches
Specification
  • Brand Hayden Automotive
  • Model 402
  • Weight 1.6 pounds
PROS

Exceptional cooling

Superior reliability

Perfect size for many applications

CONS

Looks can be undesirable

It should come as no surprise that an offering from Mishimoto is our Best Premium pick. This brand is wildly popular across many automotive industry segments for its ability to produce the best cooling solutions for virtually any platform. The cooler we are highlighting here is an excellent example of its ability to improve the factory design for a heavy-duty application. And we should mention upfront that this isn’t their only factory-replacement offering, so if you don’t run a 99-03 Powerstroke, you can likely find a Mishimoto cooler for your diesel truck or otherwise. This stacked-plate cooler bolts right in place of the factory unit and are proven to reduce temperatures by 10-degrees Fahrenheit. Not only that, it offers 265-percent more fluid capacity than the factory unit.

The price point is going to scare many folks away. But, there’s simply no replacement for the fit and finish of a factory unit and undeniable gains.

Key Features
  • Stacked-plate design
  • Factory replacement for 99-03 Ford Powerstroke
  • Proven to cool better than factory unit
Specification
  • Brand Mishimoto
  • Model MMTC-F2D-99SL
  • Weight 19 pounds
PROS

Enhanced cooling

Enhanced capacity

Easy installation

CONS

Premium price point

Most won’t be surprised that Mishimoto makes back-to-back entries on our list. But instead of an application-specific offering, this time, we are highlighting one of its universal systems. There are many things to love about this kit, but the hardware makes it worth considering. This is a universal kit, so it is similar to others, but the hose and clamps that it comes with are just a bit more reliable than some others. That isn’t to say some vehicle owners may use different hoses and clamps, but it is better than others. Despite this and the fact that the brand snags our Best Premium award, this model has an excellent price point. The cooler’s further details include its traditional tube-and-fin construction and measures 12 inches x 10 inches x 0.75 inches. We should also add that Mishimoto’s lifetime warranty backs this cooler despite having a relatively low price tag.

The overall size of the cooler does limit its use in many applications. The good news is that there are other sizes to choose from if your application calls for different dimensions.

Key Features
  • Tube and fin design
  • Backed with lifetime warranty
  • 12 inches x 10 inches x 0.75 inches
Specification
  • Brand Mishimoto
  • Model MMTC-TF-1212
  • Weight 2.27 pounds
PROS

Universal fitment

Premium construction

Decent hardware

CONS

Dimensions may be too big

Moving on, we’re onto yet another excellent offering from Hayden. Again, this brand is known for offering high-quality coolers, and we don’t want to misrepresent them by only featuring a budget-friendly option. This particular cooler features dimensions of 11 inches x 6 inches x 0.75 inches and is a perfect fit for compact to midsize cars. But, here again, we find that measurements do not limit performance, and this cooler will work with many trucks and SUVs. Furthermore, it is a plate and fin design and uses patented internal turbulation to increase heat transfer without causing a pressure drop. One more thing you’ll love is the inclusion of an integrated bracket to make mounting easy. Well, that and its affordable price tag.

However, not all hardware is included, and you will need to order the necessary coupler to finalize the installation. If you don’t know this ahead of time, it can postpone your project.

Key Features
  • Plate and fin design
  • Patented internal turbulation
  • Measures 11 inches x 6 inches x 0.75 inches
Specification
  • Brand Hayden Automotive
  • Model 676
  • Weight 2.15 pounds
PROS

Exceptional cooling

Affordable price

Integrated bracket

CONS

Does not include coupler as shown

Alright, so now we have an entry that clearly states its compatibility with transmission fluid and engine oil. So, if you were looking for a cooler that has flexibility, this is it. This offering by B&M measures 11 inches x 5.75 inches x 1.5 inches, and that gives it far more cooling capabilities than many other offerings. Not only that, the stacked-plate design aids in cooling abilities as well. Furthermore, this design is far more resistant to damage making this an excellent offering for applications that see hard use. It is effortless to install and provides an excellent fit and finish because it comes with integrated bracketry.

This cooler does what it says and sells at a reasonable price. But, as with many aftermarket coolers, the hardware it comes with is subpar in the eyes of many and will need replacement.

Key Features
  • Stacked plate design
  • Integrated bracketry
  • Measures 11 inches x 5.75 inches x 1.5 inches
Specification
  • Brand B&M
  • Model 70264
  • Weight 4.2 ounces
PROS

Excellent cooling

Reasonable price

Can cool transmission fluid and oil

CONS

Included hardware is subpar

Don’t worry, Derale is getting a mention on our list. After all, it wouldn’t be right to talk about cooling without tipping our hats to this industry leader. The cooler we are highlighting is an excellent upgrade for trucks and SUVs. It measures 11 inches x 12 inches x 0.875 inches and uses a plate and fin design to offer maximum cooling capabilities. Another detail is the inclusion of embossed turbulators to enhance heat transfer. Reliability and performance are backed by furnace-brazed aluminum, and the unit is held firmly in place with an integrated mounting bracket.

Everything about this cooler is of exceptional quality. However, many users report replacing the hose and other hardware that it comes with. This is typical of a universal offering but is still something you want to be aware of.

Key Features
  • Plate and fin design
  • Integrated bracket
  • Measures 11 inches x 12 inches x 0.875 inches
Specification
  • Brand Derale
  • Model 13504
  • Weight 2.42 pounds
PROS

Excellent cooling

Easy to install

CONS

Included hardware is subpar

This Hayden Rapid-Cool transmission cooler is an excellent update to make if you’re looking to aid the factory cooling system. It measures 11 inches x 7.5 inches x 0.75 inches and uses a plate and fin design to keep your transmission at safe temperatures. Its thin profile makes it easy to fit under pretty much any hood, but the wide surface area promotes performance. Owners of pretty much anything from compact cars to pickups will get good use out of it, even if they intend to do some towing. That said, it comes with everything you need to hook it up and does have an integrated bracket to keep everything nice and tidy.

This is a budget-friendly option, and while it comes with many mounting supplies, you’ll still need to invest in hose and couplings. This factor does depend on the application, but it is something to be aware of.

Key Features
  • Plate and fin design
  • Integrated bracket
  • Measures 11 inches x 7.5 inches x 0.75 inches
Specification
  • Brand Hayden Automotive
  • Model 677
  • Weight 2.3 pounds
PROS

Excellent cooling

Easy to install

CONS

May call for additional hardware

As we reach the end of the list, we will highlight a heavy-duty universal cooler that is a perfect upgrade for towing applications. If you are running any pickup and spend time hauling toy haulers and small trailers, this is the cooler for you. It measures 8.5 inches x 22.75 inches x 1.25 inches and uses a stacked plate design to double the cooling of other brand models. And while it is a popular update for truck owners, it makes target racing applications as well. That said, it is geared toward keeping transmissions cool in harsh environments, which is something the targeted audience cannot overlook. It’s also worth mentioning that this unit features integrated brackets and comes with a range of useful mounting materials.

Of course, the price is very high for a universal unit and will turn away many potential customers. However, the size and design offer performance many cheaper units cannot.

Key Features
  • Stacked plate design
  • Integrated bracket
  • Measures 8.5 inches x 22.75 inches x 1.25 inches
Specification
  • Brand Tru-Cool
  • Model LPD47391
  • Weight 1.76 ounces
PROS

Superior cooling

Easy installation

CONS

Premium price tag

Best Transmission Oil Coolers Buying Guide & FAQ

A lot of folks already know what they want and can get to work setting it up. And the fact of the matter is that transmission oil coolers aren’t all that complicated. But that doesn’t mean there aren’t tips to share, nor does it hurt to review.

Chances are you’re wondering if you need to run a transmission oil cooler on your manual transmission. The answer depends on the application. ATF (We strongly encourage beginners to check our guide to Automotive Abbreviations) and gear oil behave similarly when they heat up, and either can benefit from the addition of a cooling system. However, manual transmissions generally don’t need cooling unless subjected to extreme conditions such as endurance racing or heavy-duty work.

But it never hurts to be safe. And with that out of the way, we can turn our attention to helping you get the best cooler for your application.

Benefits of a Transmission Oil Cooler

Let’s start by talking about why you need a transmission oil cooler. We already know that it prevents overheating, but we didn’t talk about how that prolongs the life of your transmission and preserves optimal performance.

Both manual and automatic transmissions are reliant on fluids to operate correctly. Their lubricating properties help the internal workings as they provide motion and switch gears. But unlike regular gear oil, ATF has more jobs to do than create a barrier between metal parts. Not only that, by nature, automatic transmissions generally run much hotter. Therefore, cooling system additions and updates are far more prevalent with these applications.

In either application, running outside of operating temperatures breaks the fluids inside a transmission down. When this occurs, their performance goes with it. Metal to metal contact increases, creating excessive wear. Too much heat will also negatively impact shifting and eventually destroy the transmission. Long story short, you’re better off installing a transmission oil cooler before you spend money rebuilding or replacing that gearbox.

  • Keeping fluid with operating temperature ranges keeps the transmission functioning as intended.  
  • Proper fluid temperatures protect vital components from excess wear, effectively preserving the transmission’s life. 
  • Overheating a transmission can cause catastrophic failures, and a cooler works to prevent this.
 Mechanic Checking Transmission Oil Cooler

Types of Transmission Oil Coolers

There are different types of transmission oil coolers available to you. Which to choose depends on the application. Luckily, we can break up the offerings into two simple categories, and which works best for you comes down to your application and whether or not it came with a transmission oil cooler is factory equipment. Custom builds are subjective to a whole different form of thinking, and depending on the circumstances, you may be able to go either way.

Factory Replacement

Your automatic transmission may already have transmission cooling lines that tap into the radiator. But, this is not what we classify as a factory transmission cooler. Towing and work truck applications are the most likely candidates to come with a factory transmission cooler that mounts to the front of the radiator and functions as an entirely separate cooling apparatus.

Aftermarket suppliers are aware of this and offer transmission oil coolers that mount in place of the factory unit. The factory unit may fail when an excessive load is placed on the system, so you must upgrade when necessary. Luckily, the installation process is straightforward, but this type of unit’s price is generally much higher than a universal cooler.

Universal 

If the factory configuration offers transmission oil cooling, it is most likely through the radiator. That means adding a cooler generally means using a universal one. These coolers tap into the existing cooling system on automatic transmission and use a simple mounting system to fasten to the radiator. Though there are a few additional steps compared to installing a factory replacement, the process remains relatively simple.

It is also worth noting that if you add an oil cooler to a manual gearbox or differential, you will use a universal option. If this is your intention, it is essential to ensure you select a model that is compatible with gear oil and not just ATF.

What to Look for When Buying Transmission Oil Coolers

The entire process of selecting a transmission cooler is a bit of a balancing act. And honestly, overthinking it is the only way to create confusion. It is an enhancement to the vehicle, but it depends on a straightforward concept.

You have to remember that all you’re trying to do is keep the fluid cool enough to preserve operation. With that in mind, there are only two real features to keep an eye on. Those features are the physical size of the cooler and what fluids it will work with. Once you establish those parameters, you can move onto other features that’ll make life easier.

We should mention that adding a cooler may not be the solution to all your problems. If you are looking for further advice, you should consider reviewing our guides on Transmission Additives, the risks of Too Much Transmission Fluid, and how to Add Transmission Fluid.

Man Hands Holding Transmission Oil Cooler

The Most Important Features of Transmission Oil Coolers

That brings us to our next category, which is discussing the most critical features of a transmission oil cooler. Again, size and fluid compatibility is the upfront concern. But that doesn’t mean there aren’t other features to pay attention to.

Keep in mind that the layout and performance of the cooler vastly outweigh the price. Making cuts to the performance to save a few dollars now can cost you thousands in the long run. So, if the cooler you need is a few dollars more than the others, you should just spend it now and save yourself the heartache.

Fluid Compatibility

Out of the gate, the first thing to concern yourself with is whether or not the cooler you are looking at can work with the fluid you need it to. Many offerings can work with gear oil and ATF, but that’s not always the case. Many coolers can only work with one or the other, which isn’t always made clear by the manufacturer.

Therefore you must read the fine print and get this detail first. Otherwise, it doesn’t matter if the cooler works great. If it can’t cool the fluid you need, it’s nothing more than a waste of money.

Size

The size of the cooler is critical on two planes, and selection becomes a balancing act. For this section, we will talk about the size concerning the ability to cool the oil or fluid.

Bigger coolers can bring temperatures down much more effectively than smaller ones. But that isn’t to say that bigger is always better. Bear in mind that ATF and gear oil have an optimal temperature range, and you want to keep the fluids within this range to preserve performance.

If you run a fluid too cold, its properties may also be affected in a similar but opposite way that negatively impacts your transmission. As a rule of thumb, you want to keep transmission fluid temperatures in line with engine temperatures, and the best cooler for your application is the one that can do precisely that.

Application Compatibility

The other factor that size determines is whether or not it can fit in the vehicle. Remember that you have a set amount of room to work with, and the cooler needs to fit within a given area.

When selecting a universal style radiator, you should note the measurements and compare it with the amount of room your application gives you to work with. 

You can also read reviews to see how well it fits with your particular application. If you are working with a factory replacement style cooler, you can likely skip this step unless you have other auxiliary cooling systems mounting in the same area.

Mounting Solutions

Last but not least, you want to look at how the cooler mounts to the vehicle. In almost any case, a physical mounting bracket is a superior option. Not only does it provide a more secure mounting system, but it looks much more professional.

That isn’t to say that systems that work without a bracket aren’t viable options. In most instances, they work just fine and don’t look all that out of place. Ultimately, this is one thing you can leave up to personal preference and balance with your budget. But generally speaking, a bracket doesn’t hike the price up much higher.

The Best Transmission Oil Coolers FAQ:

Again, transmission coolers aren’t all that complicated, but to recap and begin bringing this discussion to a close, we’d like to visit a few frequently asked questions.

Q: Can a transmission cooler be used as an oil cooler?

If the cooler you select is compatible with oil, it can be used to do so. If you are using it to cool oil, you may need an auxiliary oil pump for it to work. 

Q: How do you install a transmission oil cooler?

The installation process can vary based on the model you select. However, it’s usually as simple as tapping into the transmissions existing cooling system and mounting it to the radiator. 

Q: Where is the transmission oil cooler located?

Transmission oil coolers typically mount near or on the vehicle’s radiator. 

Our Top Pick

The B&M 70268 SuperCooler Automatic Transmission Cooler takes our top pick because of the pricing and the range of applications it covers. It is only compatible with automatic transmissions, but adding a cooler to a manual transmission is relatively uncommon outside of racing and heavy-duty uses. That said, this cooler pretty much hammers the nail for most users with a slightly worked up vehicle and are looking for means to keep their transmission safe.

Final Thoughts

While the B&M 70268 SuperCooler Automatic Transmission Cooler is our top pick, we know that the Hayden Automotive 402 Ultra-Cool Tube and Fin Transmission Cooler is hugely successful because it offers excellent performance at a low price.

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