Some automotive enthusiasts believe that you do not have to service an automatic transmission in the traditional sense. In other words, they may believe that it is simply acceptable to drain out the old fluid and replace it with a new one if you want to maintain the life of this crucial component. But while these complicated systems are undoubtedly well built and designed to last, you may be only doing half the job if you simply drop the transmission pan and subsequently replace the fluid. This is because some of that fluid (and a good deal of dirt) will be trapped within the torque converter. So what should you do instead?
The Problem Accumulates
A torque converter sits in between the rear of the engine and the transmission system. Inside this part is a propeller that spins at a very high speed and acts as a centrifuge. As it builds up the pressure necessary to help the vehicle change gears automatically, a tremendous amount of fluid is thrown against the outer casing. The fluid continues to circulate, but any tiny dirt particles will eventually collect around the outer casing of the torque converter. When the vehicle is not in use, temperatures lower, and the system begins to dry out, those dirt particles will coagulate and will eventually stick to the side of the casing.
The Risk Factor
At some stage in the future, however, larger particles of dirt may begin to flake off, and they will then be carried through other parts of the transmission. Due to their size or consistency, they may begin to block tiny passages or make the fluid less efficient. This may cause a buildup of excessive heat, leading to wear and, perhaps, failure.
Half a Job
If you simply drop the transmission pan and collect the old oil, some oil will remain within the torque converter, but crucially, so will that dirt. Instead, you should use a special machine that can be connected to the transmission. This machine will gather ALL of the fluid but will also clean the interior walls of the torque converter. To do this, it will use a powerful chemical designed to soften the dirt so that it flows out and into the machine.
Way to Get This Done
Unless you have one of these expensive machines in your garage, you will need to take the vehicle to local automatic transmission services. If you do so, you'll be happy that your transmission system is as clean as possible, which will help it last for the life of the vehicle.
I've been running an auto service shop for the past 30 years. The trends in cars have changed a lot over that time, and cars are becoming a lot more complicated and automated. People can't fix many items on their own cars any more as you need a computer to diagnose most issues. People use their cars a lot more these days as we live further away from workplaces and schools so it's important for me to be able to get cars back quickly. I have had to keep learning about how the new cars run and I keep a lot of hints on this site so you can all learn the things you can do to make your cars run better.