Automatic Transmission Maintenance

Like the human body, your vehicle runs on fluids: gas, engine oil, lubricants and the lesser-known transmission fluid. Without a sufficient supply of all the above, your vehicle can come to a grinding halt or, worse yet, a vital and expensive component completely dies.

ATF Check
Even though your automatic transmission is one of the least conspicuous components in your car, it's a prime example of the potential problem of ignoring those precious automotive fluids. You're probably pretty good about regularly checking your engine oil, so we're going to talk about monitoring the fluid that keeps your transmission running cool and smooth. The whole procedure is fairly simple, and only slightly different than evaluating your oil level.


Automatic transmission fluid, or ATF, is also checked with a dipstick, which may or may not be labeled "TRANS" or "ATF." Sometimes, the dipstick handles are color-coded—yellow for engine oil, and red for trans fluid. If your vehicle's two dipsticks aren't labeled or color-coded, you can tell by each of their locations which one goes to the oil reservoir and which one goes to the ATF. The oil dipstick is generally close to the center and/or front of the engine compartment and the stick tube goes to the bottom of the engine. The ATF dipstick, on the other hand, can usually be found near the rear or off to one side in the engine compartment. (Obviously there are exceptions to this rule, so look in your owner's manual if you're still not sure.) Another clue to identify which is which is color. Motor oil is amber to brown; ATF is either light red, pinkish or gold.


Once you've determined where the ATF dipstick is, the next step is to make sure your vehicle is parked on a level surface and the transmission is warmed up—a 10-minute trip around the block is enough to reach the "warmed up" temperature. Unlike checking your oil, which requires that the engine be turned off, leave it running at idle. With your foot on the brake pedal, run the transmission through all gears and back to park or neutral, depending on the instructions in the owner's manual. Some auto manufacturers know that owner's manuals have a way of disappearing and have stamped terse instructions right on the ATF dipstick blade. Make sure your parking brake is on as well.


The reason to have the engine running and all the gears engaged before you check the ATF level is to make sure that all the hydraulic chambers in the transmission are filled with oil and the fluid is circulating normally. This should ensure that your fluid-level reading is accurate.