Flush it or Forget it
by Pat Goss
For most drivers automatic transmissions make sense, but once you own one, you have to make a decision about maintaining it. And that means you have to decide whether or not to flush your transmission, or wait until later in the life of the vehicle and flush your wallet big time. I elect to flush my transmissions.
You see, back in the day what you used to do was you would drop the transmission pan, you'd replace the transmission filter, put a new gasket in it, and replace oh, maybe a quarter or a third of the total fluid in the transmission. Didn't really do anything and it didn't clean anything, and cleaning is really important. You see, here we have a torque converter. We know the term, it bolts to the back of the engine, and it uses hydraulic pressure to connect the engine to the automatic transmission. See this portion of the torque converter spins at the same speed as your engine, so if your engine is turning three thousand RPM, so's the torque converter. And it's filled with fluid, and the fluid is circulating as well.
Now, what that means is that this acts like a centrifuge. And any dirt particles that are in the fluid get flung out until they collect around this outside area of the torque converter. Now unless you flush, there's no way to ever clean that away. And if it isn't cleaned away, eventually it will build up to a point where it begins to flake off, those flakes can travel through the transmission, block fluid passages, cause slippage, slippage causes heat, heat kills transmissions. It's just that simple. Cleanliness is the key.
See we never want to have our fluid looking like this if we can avoid it. What we want our fluid to look like always is brand new, and that means we have to flush it. We should flush it every twenty-four to thirty thousand miles. And make sure the shop that does it uses the appropriate fluid for your car. One size doesn't fit all, and there isn't a chemical that you can dump into a universal fluid that'll make it fit all cars. That's foolishness.
Now here's a typical flush machine. It has hoses that connect into the cooling lines of the transmission. All of the old fluid is drawn out of the transmission and quarantined inside the machine, and it's replenished with new fluid. But the big difference, this machine uses chemicals that clean the inside of the transmission. It softens all of this dirt, the dirt is trapped in the machine, your transmission is clean. It can double, triple, quadruple the life of the transmission. In many cases, it will make the transmission last the life of the car.