What Is The Best Transmission Cooler? (Guide) – 2018 Reviews
Fitting your car with a transmission cooler is a big deal. If you don’t pick the right cooler, your transmission will overheat and cause problems for the rest of your drivetrain. If you do pick the right cooler, you can expect your car’s critical parts to last much longer.
But what traits do you need to look for in a transmission cooler? Which transmission coolers are winners, and which will take down the rest of your vehicle when they fail? In this article, we’ll discuss a few of the strongest transmission coolers and explain why they’re so great.
Transmission Cooler Reviews – Top 7 Picks
Our #1 Pick – Hayden Automotive 678 Rapid-Cool Plate and Fin Transmission Cooler
The Hayden Automotive 678 Rapid-Cool Plate and Fin Transmission Cooler is a standard and effective cooler which is ready for anything from a pickup truck to a motorhome.
- Easy to install
- High towing capacity
- Passive cooling system
- Not universally compatible
The Hayden 678 uses a plate and fin-based heat sink which is qualified for GVWR up to 24000 lbs and 5000 lbs of tow. The turbulated fins help to increase the rate of heat transfer from the transmission to the unit while also projecting as much of it as possible into the outside air immediately afterward.
Thanks to the pre-drilled mounting brackets on the edge of the unit, it’s easy to install with a few minutes and a screwdriver. The main issue with this cooler is that not all vehicles are compatible with the base model, so you’ll need to check Hayden’s reference to see if your vehicle fits.
The other note regarding this cooler is that it uses ATF fluid rather than gear oil. On the inside of the unit, the fluid is trapped to help heat exchange from one side of the fins to the other side facing the outside.
You shouldn’t need to worry about this technical detail unless you were planning on using the Hayden on a manual transmission. Manual transmissions seldom need cooling aid, but when they do, they need a cooler which uses gear oil, so this unit is not compatible.
Our #2 Pick – B&M 70268 SuperCooler Automatic Transmission Cooler
The B&M 70268 SuperCooler Automatic Transmission Cooler is a modern cooler with a flat stacked-plate design which disperses heat at a very fast rate.
- Safer to handle than other coolers
- High heat capacity and dispersion
- Environmentally friendly
- Poor durability
- Hard to install
This cooler is constructed from aluminum alloy and is corrosion resistant, which is a nice bonus because of the high-stress area that it sits in your vehicle. The cooler comes with an installation kit and has pre-drilled mounting holes.
While this cooler is a bit harder to install than others despite its pre-drilled mounting holes, you’ll find that the power it provides is more than worthwhile. Up to 200 psi of pressure and 13000 BTUs of heat energy can be handled by the cooler without an incident.
As with other newer transmission coolers, this cooler uses ATF liquid, so it isn’t compatible with all vehicles. The cooler is constructed with fluxless and heat-tempered alloy with multiple internal flow paths.
This means that the cooler is more environmentally friendly and also safer to handle than most coolers, which are produced at least in part with flux. Flux may contain lead, so it makes coolers more dangerous to handle than this one.
The cooler’s internal self-regulatory valve helps to redistribute the ATF fluid for optimal cooling, which makes the cooler a bit less durable but a bit more effective than others.
Our #3 Pick – Hayden Automotive 403 Ultra-Cool Tube and Fin Transmission Cooler
The Hayden Automotive 403 Ultra-Cool Tube and Fin Transmission Cooler is a simple cooler that has a basic soldered grate design with a coolant tube that is a bit thicker than normal.
- Massive towing capacity
- Superior cooling ability
- Flux-free design
- Very hard to install
- Environmentally unfriendly design
With this cooler, you’ll be able to cool the transmission of your car or pickup truck while towing up to 18000 lbs. Interestingly, this unit is ultrasonically soldered, which means that it doesn’t use any flux. The downside is that the joints are a bit less secure than in other transmission coolers.
Installing this unit may be a bit of a hassle. The mounting technology which is provided with the unit is not sufficient to fit it into most vehicles. You’ll need to supply some extra parts, and you may need to perform some extra soldering. If you are a professional, this won’t be a problem.
For amateur installation, however, this cooler is probably a bit too much of a hassle to install to be worthwhile. Its cooling characteristics are fair, but the grate-based design isn’t as effective as the fin-based design.
The cooler makes up for the grate-based design by including a thicker coolant tube than normal. This is effective enough, but if there is a problem with the car and the tube gets ruptured, you’ll have an environmental problem on your hands.
Our #4 Pick – Tru-Cool – Max LPD47391 47391 Low Pressure Drop Transmission Oil Cooler
The Tru-Cool – Max LPD47391 47391 Low Pressure Drop Transmission Oil Cooler is a compact and highly effective cooler which works great when you have pressure issues.
- Passive cooling for high durability
- Cooling increases according to need
- Simple but durable design
- Difficult to mount
- May chip if dropped
The Tru-Cool system is constructed with brazed aluminum, and guaranteed to maintain its original quality for a lifetime. This is remarkable because most transmission coolers refuse to provide such a guarantee despite advertising more sophisticated materials and designs.
The Tru-Cool cooler is the most basic fin-and-tube design, but it works. The cooling power of the unit is rated for 40000 GVW and utilizes a low-pressure drop to protect your car. The mounting system is easy to use, though it may be difficult to handle the small screws which are required.
All vehicles up to the size of an RV will be well-served by this cooler. Thanks to the ATF fluid’s self-adjusting viscosity, as the transmission heats up the cooler is more effective. At the same time, it doesn’t wear itself out by remaining active while the transmission is cool.
The core design of this cooler utilizes the ATF fluid’s viscosity to flow into the areas of greatest heat exchange. This means that the best possible routing of heat out of your transmission occurs via a chemical process rather than a physical one.
Because there aren’t any moving parts in the cooler, you can expect it to work for a very long time.
Our #5 Pick – Hayden Automotive 402 Ultra-Cool Tube and Fin Transmission Cooler
The Hayden Automotive 402 Ultra-Cool Tube and Fin Transmission Cooler is a serious tube-based cooler which is capable of GVWR up to 16000 lbs.
- Compatible with older vehicles
- Compatible with compact vehicles
- Durable design
- Not compatible with newer vehicles
Every fraction of this cooler has been pressure tested, meaning that you can have faith in its ultrasonic welds over the long haul.
While the unit is essentially an older and differently shaped Hayden 402 cooling unit as we reviewed earlier, the main difference between this unit and the newer one are the vehicles which are compatible.
The 402 is better suited for lighter and older vehicles than the 403. This means that if you aren’t sure whether your vehicle can fit a cooler, you’ll have better results with this cooler than you might with others. The downside of this cooler is that it is intended for compact and midsize cars.
The coolant is sufficient for any car, but the grate is the weak point of the unit.
Our #6 Pick – Hayden Automotive 526 Remote Transmission Oil Cooling System
The Hayden Automotive 526 Remote Transmission Oil Cooling System is a highly technological fan-based cooler which provides active cooling capability to augment excellent passive cooling abilities.
- Active cooling system for superior heat dispersion
- Adaptive cooling fan adjusts to cooling needs
- Great for vehicles that run extremely hot
- Fan will need replacement
- Basic design aside from the fan
Much like in computer chips, this cooler mounts a huge fan on top of a normal fin-and-tube heat sink to provide superior heat wicking.
In this cooler, the heat from the transmission first permeates the ATF fluid. As the ATF fluid flows through the heat sink, it is wicked away from the coolant by the fins, which project outward in every direction.
That’s where most coolers end. With this cooler, however, there’s an additional step. As the fins of the heat sink are saturated with heat and radiating it, a large fan sucks the radiated heat away and expels it from the area.
This means that even the hottest transmissions can experience relief from heat. The only downside of using a fan to wick heat is that it requires moving parts.
The hotter your car runs, the faster this little cooler will run its fan into oblivion. Fans are very inexpensive to replace, however, so if your vehicle is very hot, it may be worthwhile nonetheless.
Our #7 Pick – B&M 70264 SuperCooler Automatic Transmission Cooler
The B&M 70264 SuperCooler Automatic Transmission Cooler is a fin-and-grate system which uses a slightly older design in the name of reliability.
- Fin-and-grate heatsink design
- Cooling increases in response to backdraft
- Radiative passive heat dispersion
- Difficult to install
- Radiative passive heat absorption may lower effectiveness
This cooler is unique for its use of both fins and grates. Heat will be brought away from your transmission into the network of the cooler, which will then become saturated and radiate the heat everywhere.
When you are driving faster, this cooler will be more effective because of the backdraft which will grab heat from inside the grid.
For city driving, this cooler may not be the best choice because the amount of ambient heat radiating upwards from asphalt can saturate the cooler and leave heat with nowhere else to go.
Nonetheless, this cooler is extremely durable. It may be a bit hard to install, however. The included installation kit is comprehensive, but the inlet may prove difficult to mate with the screw.
Frequently Asked Questions
What Should I Look For In A Transmission Cooler?
The main features you should look for in a transmission cooler are cooling ability and ease of mounting. You’ll probably only have to mount your transmission cooler once, but it is simple enough that it should not require professional help.
If it does require professional help, you probably could have found a transmission cooler which was easier to install and thus much cheaper.
Above all, cooling ability is the most important characteristic. Most transmission coolers can provide at least a moderate amount of cooling, but not all can handle the cooling responsibilities in a large vehicle like an RV.
The more sophisticated the cooler, the more cooling it will provide.
How Long Should I Expect My Transmission Cooler To Last?
Most transmission coolers last a long time, but there are a number of caveats. First, the more sophisticated a cooler is, the more cooling it will provide, but the sooner it will break.
The simplest coolers are blocks of metal which don’t provide much cooling, but will never break. The median coolers are blocks of metal with fins, grates, and internal coolant. The internal coolant adds a massive amount of cooling ability.
But it also means that if the metal corrodes, the coolant will leak out and the cooler will be useless. For most people, this is an acceptable risk.
The most advanced coolers have active cooling systems which utilize valves, powered fans, and more. Valves are unlikely to break very often, but they will break and reduce the unit’s cooling ability eventually.
Fans, on the other hand, provide excellent heat wicking ability but very low reliability. For most purposes, fans are overkill.
Do I Need To Replace My Coolant?
You shouldn’t need to replace your ATF fluid in your transmission cooler until you need to replace the entire cooler.
Coolant should never be leaking out of the cooler. Nor should it ever be exposed to the air and liable to evaporate. The cooler is meant to be a closed system, and any indication of it being otherwise is a serious problem that needs attention.
If you see that coolant is leaking, be careful. The coolant is toxic to you, and it is also toxic to the environment. Remove the offending cooler as quickly as possible and contain the spill of the coolant on the ground.
Typically, coolers only leak coolant when they have been ruptured by mechanical force, such as in a car accident.
There is no need to replace any spilled coolant — the entire cooler unit is lost when there is coolant leaking. Don’t try to repair your cooler.
Which Coolant Is Best?
The best coolant for most purposes is ATF fluid. ATF fluid is compatible with the vast majority of automatic transmissions. If you have an edge case, you will probably already know about it. For manual transmissions, there are a handful of gear fluids which are more helpful.
Some manual transmissions may be compatible with ATF fluid, but most are not. The vintage of the vehicle makes a big difference with regard to the correct coolant for manual transmission vehicles, so be sure to reference the vehicle’s documentation before setting up a new cooler.
What Mounting System Is Best?
Most mounting systems are based around four screw ports. In the screw ports, some coolers provide spikes which can be placed deep inside the well so as to provide another conduit for heat to the cooler.
These spikes don’t add much cooling ability to your cooler, so don’t consider them a critical feature. Instead, they may interfere with mounting, even though they are part of the mounting system.
The best mounting systems are very simple.
So long as there is no empty airspace between the hole and the screw, a four-screw mounting bracket is more than sturdy enough the vast majority of the time. If you find a cooler which has significantly more installation than the screws and a few nuts, you may want to look elsewhere.
Avoid any epoxy or resin-based mounting systems. These are most likely to be found in the context of old vehicles made from fiberglass or similar non-modern metals.
Except in the exact vehicles they are intended for, liquid mounting systems are an accident waiting to happen, and they’re also much harder to apply than others.