A Few Words on Transmissions

If you think your street rod’s engine works hard, think about what your tranny goes through. Your transmission basically keeps your engine’s rpm’s within a usable range and transmits that horsepower from the crank to the drive wheels no matter how hard you stomp on the gas. This process generates a ton of heat, and in order to keep the heat relatively low, transmissions rely on transmission fluid to lubricate and cool the moving parts.

Sometimes the transmission fluid just isn’t enough to keep everything cool. There are times when the fluid temperature can exceed the recommended range of 170 to 200 degrees, and when this happens, the fluid begins to burn. This decreases the amount of fluid running through your transmission, which in turn can seriously damage parts within the transmission, often leaving ya stranded in the least desirable location.

Installing a transmission cooler is an extra precaution against overheating your transmission, and many people decide to use them not only in tow vehicles, but performance vehicles, as well. Transmission coolers come in many different shapes and sizes, and there are a few things to consider when choosing one.

Perhaps the most important factor to consider is the vehicle itself. How much does it weigh, and are ya going to load it up with cargo relatively often? Matching a tranny cooler to your vehicle’s gross weight is critical to allow this add-on cooler to operate properly. (You can get specifics from the pros by contacting any of the engine/trans cooler advertisers you see here in CT.)

As is the case with engine oil, AMSOIL synthetic ATF (again I mention it cuz it’s the brand I use), exceeds the performance requirements for domestic transmission fluid applications and provides automatic transmissions and power-steering units with excellent lubricating protection and better performance over a wider temperature range than conventional automatic transmission fluids. Being a synthetic, it resists thermal and oxidative degradation better than conventional transmission fluids, protecting your tranny and its internals from damaging sludge and varnish deposits. More importantly, it helps prevent component overheating and ensures cooler, smoother transmission operation.

Too low a transmission fluid temperature is not a good thing either (a fact that I was not aware of until I started to do some reading up on the subject), and again, synthetics outperform petroleum fluids in low temperature fluidity.

That said, I think there’s a good argument for getting a better education with regards to engine oil and transmission fluid coolers. The pages of CT are chock full of engine, transmission and cooler manufacturers and dealers that, unlike myself, are experts and I urge you to take the time to hit up their many websites or check in with their tech lines to bone up on the subject. Our classic pickups are large investments in both cash and effort, and anything that can be done to ensure they stay up and runnin’ is worth the time and effort needed to keep ’em that way. Stay cool, and have fun! CT