TRANS COOLER - ISUZU DMAX/MU-X / MAZDA BT50 3.0L 4JJ3

The Transmission Cooler Kit for the 3.0L 4JJ3 Isuzu D-MAX, MU-X and Mazda BT-50 (08/2020 onwards) is designed to significantly reduce automatic transmission temperatures when towing, touring or driving in demanding conditions.

Automatic transmissions generate a large amount of heat, particularly when towing caravans, hauling heavy loads, driving off-road or operating in hot climates. Excess heat is one of the biggest contributors to premature transmission wear and failure.

This upgraded transmission cooler helps maintain stable transmission fluid temperatures, allowing the gearbox to operate more efficiently and reliably under heavy loads.

The kit features a high-efficiency plate and fin transmission cooler designed to maximise heat dissipation while remaining compact enough for vehicle-specific fitment. These coolers are significantly more effective than smaller factory units and can reduce transmission fluid temperatures by up to around 30°C in demanding conditions, helping protect the transmission from heat-related damage.

By lowering ATF temperatures, the cooler helps extend transmission lifespan and maintain consistent gearbox performance, particularly in vehicles used for towing or heavy touring setups.

Why Upgrade Your Transmission Cooling?

Heat is the number one enemy of automatic transmissions. When transmission fluid temperatures climb too high, the fluid begins to break down which can lead to slipping, increased wear and eventually transmission failure.

Installing an upgraded transmission cooler helps:

• Reduce transmission fluid temperatures

• Improve gearbox reliability under load

• Maintain consistent shifting performance

• Extend transmission life when towing or touring

• Provide additional protection for tuned or heavily loaded vehicles

For owners running touring setups, towing caravans or regularly driving off-road, a transmission cooler is one of the most valuable upgrades you can add to a 4JJ3-powered D-MAX, MU-X or BT-50.