transmission bench logo


Parts Cleaning: Be Careful!

July 22, 2014

     Cleaning stuff can cause problems. Irreversible problems. Let’s take a serious look at cleaning a transmission or its individual parts. This article isn’t too long, but it is extremely important not only for your safety but also to avoid damaging your transmission.
   First of all, protect yourself. Use some form of eye protection such as safety glasses or better yet, a face shield. Even when being careful, if something can, it will get in your eyes. Wear gloves too. Many people have sensitive skin, but in general it’s not good to expose hands and arms to harsh detergents and petroleum based cleaners and solvents. I recommend the blue or black colored nitril disposable type.
    Secondly, you can seriously damage parts of a transmission using the wrong cleaning solution. For instance, soap and water will immediately oxidize bare steel components like clutch steels, shafts and bearings. Within seconds, ferrous parts such as these will begin to rust and turn an ugly orange-brown color. An even worse scenario is attempting to clean solenoids, friction plates and bands with a water based solution. Trust me, if you get water into a solenoid or any other electronic component used in a transmission, it will never work right again. Water will also attack the paper based materials on friction plates and bands. The linings will separate from the metal backing. As a general rule, avoid using water based anything around an automatic transmission.
   There is one exception: cleaning the aluminum case. Ok, I know you’re going to take the transmission case to the car wash to clean it and this is fine. Just make sure you remove all of the steel parts, even the selector shaft and parking pawl pieces. You can leave the parking hammer in but dry it off with compressed air immediately if you can.
    Now, back to what not to use. Add these substances to the list of stuff to avoid: gasoline, diesel fuel, paint reducer, alcohol, and kerosene. Technically you could clean transmission parts with these liquids but they’re extremely FLAMMABLE! Do not use them.
   I’ve found only one product acceptable to use: mineral spirits. It’s nowhere near as volatile and fumes are not too bad. Even so, use it only in a well-ventilated area.
   One last point I want to make: Even though you may be tempted to wash parts in mineral spirits without gloves, take my advice and wear them anyway. Wait until you see how even this seemingly milder solvent attacks latex or nitril gloves. You’re gonna need a box of them! Stay safe.