Transmission Coolers For RVs

RV parked in the mountains

Recreational vehicles, or RVs, are vehicles designed for use as temporary living quarters for travel, recreation, and camping. They range in size and style, from small pop-up trailers to large motorhomes with multiple rooms and amenities.

RVs can be classified into several categories, including:

    • Class A: These are the largest RVs, typically built on a bus or truck chassis and ranging from 20 to 45 feet in length. They often have multiple rooms, a full kitchen and bathroom, and can sleep up to 10 people.
    • Class B: These are smaller RVs, typically built on a van chassis and ranging from 16 to 20 feet in length. They often have a fold-down bed, a small kitchen and bathroom, and can sleep up to 4 people.
    • Class C: These RVs are built on a truck chassis with a cab-over section that extends over the driver’s area. They range in size from 20 to 35 feet and often have a separate bedroom and living area, a full kitchen and bathroom, and can sleep up to 8 people
    • Travel trailers: These RVs are designed to be towed behind a vehicle and range in size from small pop-up trailers to large fifth-wheel trailers. They often have a separate bedroom and living area, a full kitchen and bathroom, and can sleep up to 10 people.
    • Truck campers: These are small RVs that attach to the bed of a pickup truck. They typically have a fold-down bed, a small kitchen and bathroom, and can sleep up to 4 people.

RVs offer the convenience and comfort of a home on wheels, allowing people to travel and explore new areas while still having all the amenities of home. They can be used for long-term travel or for short trips and can be rented or purchased.

To keep you RV on the road for as long as possible, 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 it comes to finding a transmission cooler for your RV or camper, here are our picks for top transmission coolers for your needs!

Transmission Cooler Type of Cooler Type Of Cooler Price
Tru Cool 40k transmission cooler LPD47391Tru-Cool Max LPD47391 40,000 Plate & Fin Shop Now

Hayden Automotive 679 transmission cooler - Transmission Cooler GuideHayden 679

30,000 Plate & Fin Shop Now
B&M 70274 transmission cooler - Transmission Cooler GuideB&M 70274 29,200 (BTU) Stacked Plate Shop Now

Derale 15960

30,000 Stacked Plate w/ Fan Shop Now

Does My RV Need An Aftermarket Transmission Cooler?

While some vehicles can get by without adding an external transmission cooler, most RVs will need it simply based on their weight alone. RVs are designed as heavy-duty vehicles and have a transmission to support it, but often times, especially in the warmer months, your transmission temps will climb, and fast! 

Most vehicles utilize a transmission cooler built inside the radiator, and more heavy duty vehicles will supplement with an external cooler in front of the radiator and air conditioning condenser, and RVs are no exception.  However, the factory transmission cooler(s) may not be enough to keep you trans temps low.

Tow More Effectively

While a  transmission cooler will not increase towing capacity of your RV, it will however increase the cooling efficiency of your transmission fluid when towing.

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 For My RV?

When you are driving your RV in various environments such as inclines or in traffic, 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 RV 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 capacity.

Transmission Cooler GVW rating chart - Transmission Cooler Guide

Can A Transmission Cooler Be Too Big?

When it comes to transmission cooling and driving an RV, it’s always best to get the absolute biggest transmission cooler you can, especially if you often tow a car behind your RV.  So no, a transmission cooler cannot be too big in this situation.  

What Are The Best Transmission Coolers For RVs?

The best types transmission coolers for RVs are going to be a stacked plate or plate and fin style coolers. These types of transmission coolers are preferred because of their ability to disperse heat the effectively, and because they’re typically large, which allows for increased cooling compared to a smaller cooler.

Although these types of transmission coolers are more expensive than a simple tube and fin style cooler, they will keep your 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 in size, they may not be ideal when it comes to adequate cooling.

When adding an external cooler on your RV, it is recommended to place the cooler in front of the radiator and air conditioning condenser to allow for maximum airflow from both incoming air and the cooling fan when at low speeds or in traffic. 

Tru-Cool 40k – Best Overall Transmission Cooler 

tru cool 40k transmission cooler - best transmission cooler for towing - transmission cooler guideThe 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 RVs. 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 ideal 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 an fittings.  Smaller Tru Cool coolers use a 3/8 hose barb fitting, which makes it easier to install rubber transmission hose.

What We Like About The Tru Cool 40k:

  • GVW Rating of 40,000 pounds
  • 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

Overall, the Tru Cool 40k takes our vote for the best transmission cooler for RVs and motor homes.  Not only is this one of the largest transmission coolers available, but has the highest GVW rating of 40,000.  One of the biggest 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 in most areas in from of the radiator and condenser, but should be measured prior to purchasing to make sure.. Other than that, this is in our opinion the #1 transmission cooler for RVs.

Hayden 679 – Best Budget Transmission Cooler 

hayden 679 transmission cooler review - Transmission Cooler GuideThe Hayden 679 offers a high 30,000 GVW which makes it a great transmission cooler to use on smaller RVs that may tow cars on a dolley.  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 provides enough capacity to tow 10,000 pounds or be used on class A motor homes.

What We Like About The Hayden 679:

  • 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

Overall, the Hayden 679 transmission cooler is a great value for a transmission cooler for your smaller RV.  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.

  • Size is 3/4 inch x 11 inch x 11-5/8 inch. Compatible with OEM cooler systems
  • Class "A" motor homes, large travel trailers, 5th wheel trailers
  • GVWR up to 30,000 pounds, towing up to 10,000 pounds
  • Patented internal turbulation increases heat transfer with minimal pressure drop
  • Pre-drilled mounting brackets for easy installation

B&M 70274 – Best Stacked Plate Transmission Cooler

B&M 70274 transmission cooler - Transmission Cooler GuideThe 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 About The B&M 70274:

  • NPT Fittings for secure fitment
  • 48 cooling rows for added cooling capacity
  • Low pressure drop
  • High capacity
  • 11″ x 11″ x 1 1/2″ size  

Overall, the B&M 70274 is one of the best coolers on the market for heavy duty 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 for your RV if you’re interested in adding custom lines.  Note: you can use barb fittings and use simple rubber transmission lines as well if you prefer.

  • Rigid stacked-plate design is resistant to damage, and much better at cooling than ordinary 'fin and tube' coolers
  • Constructed from black finished lightweight aluminum alloy for maximum corrosion resistance
  • 11" x 11" x 1-1/2" racing model is rated at 29,200 BTU, and pressure tested to 200 PSI
  • Fluxless, oven brazed construction is vibration resistant
  • Multiple oil flow paths for maximum cooling efficiency

Derale 15960 – Best Transmission Cooler With A Fan 

Derale 15960 transmission cooler - Transmission Cooler Guide

Like most Derale transmission coolers, 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 About The Derale 15960:

  • 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.

Overall, the Derale 15960 is certainly in the discussion for being one of the top rated transmission coolers with a fan for RVs. With its stacked plate construction, heavy duty fan, and inline thermostat, transmission cooling shouldn’t ever be an issue. 

One of the pros 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 RV.

  • Mounts anywhere space permits. Mounting-7-1/2 x 9 inches
  • Electric fan supplies optimum airflow
  • Dramatically extends engine and transmission life
  • High efficiency stacked plate cooler


When it comes to keeping transmission temps on your RV low, 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 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 RVs will help your vehicle’s transmission temps stay cool and improve its longevity.