Towing with an automatic transmission equipped vehicle is very common. So common in fact that some heavy duty trucks and SUV’s already have a transmission cooler that can handle the added stress placed on the transmission.
When it comes to towing, you want to ensure that your transmission stays as cool as possible. It is recommended to try to keep your transmission fluid temperature in a range between 180 and 200 degrees. After 220+ degrees, you will dramatically lessen your transmission’s lifespan.
When towing, it is highly recommended to keep an eye on your transmission temperatures. The best way to monitor your transmission temperatures is to use a transmission temperature gauge. Most transmission temperature gauges are mechanically installed in the transmission pan to monitor fluid temp. There are a number of options that will simply plug into your OBD2 port and monitor the temperature via the factory gauge in the transmission’s valve body.
Do I Need A Transmission Cooler For Towing?
While some vehicles can get by without adding an external transmission cooler, most will need it. If your vehicle is designed to be able to tow, odds are there already is an external transmission cooler in conjunction to the stock unit. Most vehicles utilize a transmission cooler inside the radiator, and more heavy duty vehicles will supplement with an external cooler in front of the radiator and air conditioning condenser.
Despite the fact that vehicles have a setup for towing from the factory, this may not be enough. Depending on your tow capacity and the realistic load you will be moving, it is usually best to think about adding a transmission cooler, or upgrade the existing one. While some may argue that this is not needed, it is a matter of being overly protective of your vehicle. The last thing you want is to rely on an inadequate cooling system and have your transmission fail while on the road. Not only will you need to pay for a tow, but a new transmission as well.
Does A Transmission Cooler Increase Towing Capacity?
While there are a number of benefits of using a transmission cooler for your vehicle, the do not in crease towing capacity. Despite the fact that a transmission cooler will not increase towing capacity, it will however increase the cooling efficiency of your transmission fluid.
Towing puts a heavy strain on your transmission and increases the heat being transferred throughout the fluid. A transmission cooler that is designed for being used in towing situations will help keep your transmission fluid cooler. As long as you have a transmission cooler with a appropriate GVW rating, you can safely tow within your vehicle’s towing capacity.
What Size Transmission Cooler Do I Need?
When you are towing, your transmission fluid can certainly get warm. Because of this, you need a large transmission cooler to handle the added heat. When shopping for a transmission cooler for your tow rig, it is important to get one that has a high GVW rating. Transmission coolers are rated by their gross vehicle weight or GVW, and this can go from as little as 10,000, all the way up to 40,000 or more!
Based on the transmission cooler GVW chart shown below, the optimal transmission cooler should be at least 20,000 depending on the tow capacity.
What Are The Best Transmission Coolers For Towing?
The best types transmission coolers for towing are typically stacked plate, or plate and fin coolers because they are able to disperse heat best. While these types of transmission oil coolers are more expensive than a simple tube and fin style cooler, they will keep your tow vehicle’s transmission temps down, preventing wear and tear caused by excessive heat.
Most heavy duty transmission coolers are either plate and fin and stacked plate cooler, so they are designed to do the job right. While a tube and fin can be large transmission cooler, they may not be the best to rely on when it comes to towing heavier loads.
When adding an external cooler on your Truck or SUV, it is recommended to place the cooler in front of the radiator and air conditioning condenser. This will allow the cooler to get as much air flow as possible. Air flow will help the cooler better reduce transmission fluid temperatures before going back to the transmission.
|Name||Type of Cooler||GVWR||Price|
|Tru-Cool Max LPD47391||Plate & Fin||40000||Shop Now|
|Hayden 679||Plate & Fin||30000||Shop Now|
|B&M 70274||Stacked Plate||29,200 (BTU)||Shop now|
|Derale 15960||Stacked Plate w/ Fan||30,000||Shop now|
Tru-Cool 40k – Best Transmission Cooler For Towing
The Tru-Cool Max, or as it is commonly referred to, the Tru Cool 40k is a plate and fin style trans cooler that boasts a 40,000 gross vehicle weight rating. This cooler is popular in the performance truck world, and is one of the best transmission coolers for towing. Almost every user of this cooler experiences a significant drop in transmission cooler temperatures compared to using just the stock cooler.
There are 2 different style Tru Cook 40k coolers. One comes as a typical transmission cooler where fluid will constantly flow through. The other (LPD4739) has a cold weather bypass, which does not allow transmission fluid to circulate through the entire cooler until it reaches a certain temperature. This is best for those who live in colder climates.
Tru Cool 40k Features
The Tru Cool 40k cooler features a durable double brazed aluminum construction with precise fin spacing for efficient air flow and cooling. This cooler is designed with 13 plates for cooling and its dimensions are 8.5 x 22 x 1.25 making it one of the largest transmission coolers on the market.
The Tru Cool 40k uses 3/8 inverted flare hex fittings which makes it great for running custom transmission cooler lines with a/n fittings. Smaller Tru Cool coolers use a 3/8 hose barb fitting, which makes it easier to install rubber transmission hose.
What We Like:
- GVW Rating of 40,000
- Includes cold weather bypass – Perfect for towing in colder climates
- Fitting type – The inverted flex flare provides a more secure connection to to transmission cooler lines assuming the right fittings are used
- Can bypass the stock cooler – This cooler is large enough to use as a stand alone transmission cooler
What We Don’t Like
- Can be hard to mount – While the size helps it get its 40k GVW rating, this can be an issue depending on how much space you have to work with
Overall, the Tru Cool 40k takes our vote for the best transmission cooler for towing. Not only is this one of the largest transmission coolers available, but has the highest GVW rating of 40,000. One of the best benefits is that you have the option to have an internal cold weather bypass or not depending on which model you buy.
The only thing we can see as the negative of this cooler is getting it to fit on your vehicle. This should be easy to mount on most full size trucks, but SUV’s may have a harder time getting it to fit. Other than that, this is in our opinion the best transmission cooler for towing.
Hayden 679 – Best Budget Transmission Cooler For Towing
Like described in our buyer’s guide, the Hayden 679 offers a high GVW, which makes it a great transmission cooler to use when you’re towing. The Hayden 679 is a plate and fin style cooler designed for easy installation. The cooler comes as a complete kit with extra transmission hose, fittings, clamps, and zip ties.
The cooler’s dimensions are 11 5/8 x 11 x 3/4 and is rated at 30,000 GVW. This provides enough capacity to tow 10,000 pounds or be used on class A motor homes, large travel trailers, or with 5th wheel trailers.
What We Like:
- Size – The size of the cooler makes it easy to mount in most locations on your truck or SUV.
- High GVW Rating – The Hayden 679 offers a 30,000 GVW rating which is plenty for most common applications.
- Cost – This cooler provides an excellent value and is the perfect choice for those looking for a higher capacity cooler at a lower price.
- Comes as a complete kit with extra hose, clamps, and mounting hardware
What We Don’t Like:
- Fittings – The Hayden 679 has basic barb fittings. While this isn’t a bad thing, you will just need to make sure your rubber line is secure to prevent leaks.
Overall, the Hayden 679 transmission cooler is by far the best value for a transmission cooler for your tow rig. With its thinner design, the cooler is easy to install on your vehicle with little to no modification. Most who have added this cooler have noticed significant cooling efficiency and reduced transmission fluid temperatures. We highly recommend this cooler for the budget minded who need extra cooling capacity.
B&M 70274 – Best Stacked Plate Transmission Cooler For Towing
The B&M 70274 super cooler is a stacked plate style cooler with a very robust design. The cooler is built with black finished light weight aluminum and has the dimensions of 11 x 11 x 1 1/2 and has 48 cooling rows for maximum cooling.
The B&M 70274 is equipped with 1/2″ NPT fittings which will require you to go out and purchase extra fittings, but if you are purchase a transmission cooler for added piece of mind, this should not deter you from buying this cooler. The NPT fittings, when installed correctly, provide a worry and leak free connection. This possibly eliminates the use of rubber transmission line which is prone to leaking over time.
Another added benefits of this cooler is that, similar to the Tru Cool 40k, colder, thicker fluid will be routed differently than warmer, thinner fluid. This helps to prevent over-cooling and to allow transmission fluid to be directed through the core as temperatures increase.
What We Like:
- NPT Fittings for secure fitment
- 48 cooling rows for added cooling capacity
- Low pressure drop
- High capacity
What We Don’t Like:
- The 1 1/2 inch thickness can make it harder to mount compared to the Hayden 679
- Added cost for fittings – this will lead to more work and time needed to get this cooler installed
Overall, the B&M 70274 is one of the best coolers on the market for towing applications. Its design and size are great for keeping transmission temperatures low. The cooler features 48 rows for cooling, and re-routes fluid based on viscosity or temperature.
If you are fine with having to purchase extra fittings, this cooler will provide a worry and leak free connection. After having previous experience with the B&M 70274, we highly recommend this cooler.
Derale 15960 – Best Transmission Cooler With A Fan For Towing
The Derale 15960 transmission cooler is a stacked plate style cooler with 25 cooling rows and an 8″ fan that flows 500+ CFM. This combo was designed for maximum transmission cooling efficiency. The cooler itself is rated for 30,000 GVW, so with the addition of the fan, this is one serious transmission cooler.
This cooler comes complete with an installation kit that includes 10 ft of transmission hose, fittings, and clamps to aid in the mounting process. While the cooler comes with the fittings and extra rubber hose, the fitting on the cooler are -8AN, so custom lines with AN fittings are certainly an option as well.
One of the nice features of the Derale 15960 is that it comes with a thermostat that will automatically turn the fan on when transmission temperatures flowing into the cooler reach 180 degrees. This is great to have for the user who is looking for a 100% worry free transmission cooler.
What We Like:
- Size – The size of the cooler makes it easy to mount in most locations.
- Stacked plate style cooler for maximum efficiency.
- 180 degree inline thermostat that automatically turns fan on.
- Comes as a complete kit with extra hose, clamps, and mounting hardware. This cooler can be used with barb fittings or custom lines can be used with AN fittings.
What We Don’t Like:
- Price – While this cooler is on the higher end of the cost scale, the cooler certainly is worth is in terms of value.
Overall, the Derale 15960 is certainly in the discussion for being one of the top rated transmission coolers with a fan for towing. With its stacked plate construction, heavy duty fan, and inline thermostat, transmission cooling shouldn’t ever be an issue. We have seen a number of dually drivers who tow heavy 5th wheel loads utilize this cooler in addition to their factory cooler and never have any issue.
One of the best aspects of this cooler is that is comes equipped with -8AN line fittings, so it is easy to plumb custom lines to increased cooling capacity. This cooler will handle anything the most extreme conditions, and because of that, it is on our list of being one of the best rated transmission cooler for your tow rig.
How To Cool A Transmission Down When Towing
By now, you know that you need to monitor transmission temps, but what happens if you see that the temperatures are still higher than you’d like? The first thing to take note of is if you are still in the temperature range.
If your vehicle’s transmission fluid temperature is starting to creep past the recommended range, there are a few ways to help it cool and prevent failure. By acting quickly, you can keep your transmission from overheating and severe damage.
Tow Haul Mode
Most trucks and SUV’s have a feature called Tow – Haul mode. This is used to change how the transmission shifts under a heavier load. It is common for Tow Haul mode to allow to reduce shift cycles as it changes shift points to a higher RPM. This is done to help you stay in the power bang while towing a heavier load.
Not only does tow haul mode help with transmission shift points and power, but also may disengage overdrive. This helps prevent burning out the overdrive gear, but will still allow the torque converter to lock up under load.
Use A Lower Gear
The best way to prevent your transmission from getting too hot while you’re towing is to use a lower gear. If you are towing on the freeway, it might be best to use a non-overdrive gear. For example, if you have a 4 speed transmission, it is often recommended to use 3rd gear rather than 4th. This is done to prevent constant downshifts.
Since you are towing and adding additional strain, the transmission will have a tendency to want to downshift to keep the motor in the power band. This is most common on any type of grade. If you know you are going to be going through an area that is not flat, see how often the vehicle will downshift and if need be, manually select a lower gear.
When it comes to towing with your vehicle, it is highly recommended to install a higher capacity transmission fluid cooler than what comes standard. This will not only help keep your transmission cooler, but help in most daily driving situations.
The common thing people hear when it comes to buying a transmission cooler is “get the biggest one you can fit”, and this is true. Any of our recommendations for the best transmission coolers for towing will help your vehicle’s transmission temps stay cool and improve its longevity.