Things to know about fluids before you pour them in your transmission

Words: Cam Benty

The world of transmissions has greatly evolved since the days of the classic muscle cars, when you simply flowed in some random ATF and set out for parts unknown. Today, not only are the transmissions far more complex, the fluids used to keep them “well oiled” are highly sophisticated.

We recently had a chance to speak with Lake Speed Jr. from Driven Racing Oil about transmission fluids for both automatic and manual transmission vehicles. While the advertising hype will often tout the benefits of various products based on limited use of the facts, we hope you will find this information extremely helpful next time you think about filling your transmission.

Here are some critical questions every performance automatic and manual transmission owner should know and fully understand.

What is the difference between old school and current automatic transmission fluids?

Some fluids are vastly different. For example, a modern Dexron VI fluid features a different viscosity and co-efficient of friction compared to an old-school Ford Type F. These two fluids are completely incompatible. The fluid required to run a modern 8- or 9-speed automatic utilizes different chemistry than what is needed to run an old-school 3- or 4-speed automatic.

What should late model transmission owners know concerning internal wear with electronic transmissions?

The biggest issue with fluids and electronic transmissions relates to seals and wiring. Some fluids can soften and degrade seals, as well as the plastic wire covering. If the seals fail, so will the transmission in due time. If the wiring shrouds fail, all kinds of bad things can happen.

How can vehicle owners increase the longevity of these sophisticated transmissions (manual or automatic)?

There are several ways to accomplish this. First, by designing the fluid to be part of the transmission, the longevity and performance of the transmission can be enhanced. Second, by not restricting the performance of the transmission to the lowest price multi-vehicle ATF at the parts store, OEMs are unlocking the benefits of higher quality base oils. For example, a high-quality, full-synthetic Dexron VI will last longer and protect better than a conventional multi-vehicle ATF.

What about “yellow” metals found in manual transmissions? Is there anything special about their care?

Old-school manual transmissions with yellow metal synchronizers must run fluids compatible with yellow metals. If you use the wrong fluid, the synchronizers will not properly function and can be badly damaged. If you are unclear as to what the right fluid is, you can call our tech line for more information, we’re happy to help.

Young vs. Old Transmission Science

Beyond the fact that both the old-school Turbo 400 and modern Dual Clutch can officially be defined as transmissions, they have little in common. One transmission is an automatic, and the other is an automated manual transmission, but the differences go beyond just the mechanics.

The fluids for these transmissions are also very different. The increased use of application-specific transmission fluids led Driven Racing Oil to develop a new line of its own to meet these specialized needs.

For the old-school transmissions, Driven now offers AT3 for automatic transmissions that require Dex/Merc III ATF and the new 80W-90 GL-4 gear oil for manual transmissions with yellow metal (brass or bronze) synchro rings. Both “old-school” fluids combine modern technology and proven additive systems to provide the best protection and performance for the old-school applications.

For modern transmissions, Driven offers an even wider selection of products to meet the increased complexity of modern vehicles. AT6 surpasses the GM DEXRON IV specifications, and Driven’s 75W-90 GL-5 gear oil is compatible with straight-cut transmission gears, limited slip differentials, and hypoid gear sets.
Not only are all of the new Driven products compatible with these applications, they are also track tested and performance proven for use in both street and track environments.

In the end, the key to increased performance and longevity is utilizing the proper fluid for the application. The new offerings from Driven provide the performance and longevity you need by nailing the needs of each specific application — old school powerglide or modern T56.

Source: Driven Racing Oil, drivenracingoil.com