One thing most drivers know is that the most expensive part of your car apart from the the engine will always be the transmission - even more so with automatics. With manuals costing anything from RM900 and automatics reaching the thousands, it only makes sense that we should do whatever it takes to ensure it never breaks down.
Imagine you're holding two small tennis balls. You can happily carry these balls along with you and you might even be able to juggle the balls as you walk. What happens when you replace these tennis balls with bowling balls? You will struggle to hold these balls as you walk and you'll most likely sweat and feel all hot and flustered by the end of your journey. The same applies to cars! Without any load, your transmission will happily transfer your engines power to the wheels without a fuss. But throw in a couple of hard revving trackdays, tow a trailer or a car, or even just drive hard up (or down) Genting and you'll stress your transmission beyond what it was initally designed for. Automatic Transmission Fluid (ATF) will start to heat up and once it reaches its maximum temperature, it'll start to breakdown or evaporate and your transmission will not get the lubrication it needs to run properly or efficiently, which will result ultimately in a massive breakdown of parts and a really hefty repair bill.
In comes the transmission cooler. Most stock automatic car transmission coolers are just a single line of copper that's part of the radiator located in front of the radiator which quite frankly is useless for cooling a hot transmission. Aftermarket transmission coolers are essentially mini radiators that have more cooling fins to help cool your ATF.
Interested in DIY-ing one? Read more here.
Just a note :
Automatic transmission is Hydromatic (powered by moving fluid). Autos have a built in pump that circulates ATF in the gearbox. The Torque Convertor is designed in such a way that there is a lot of heat generated. Hence transmission coolers would help greatly.
Manual Transmission is stationary and rotational. Air cooling is more than sufficient however if you want to install a cooler, it's possible but you'll need to add an additional external pump to circulate the gear fluid.
