You should flush your transmission every 30,000 miles or so, draining the fluid and replacing it with new. 30,000 miles can be hard to keep track of, though, particularly as it may take three or four years to get there. And in some cases, you might need the change sooner. How do you know when your transmission needs to be serviced?
Here are five signs that you need new transmission fluid.
- Grinding Noises. If you hear a grinding noise in your transmission as you’re driving, it may indicate a couple of things. Your transmission fluid may be low, in which case it should be replaced. Or there may be a buildup of dirt, grease, and other contaminants, in which case, the transmission needs a flush. Check your transmission fluid levels, and notice what color the fluid is. If it’s red, it’s fine. If it’s brown or black, you need a flush.
- Leaking. When you pull out of your driveway or garage, do you see dark, oily spots on the ground where your car just was? If so, it’s a sign that your transmission fluid is leaking. First, you need to get the leak repaired as quickly as possible, to avoid further damage. Then, you’ll need new transmission fluid, to replace what’s leaked out.
- Slipping or Other Gear-Shifting Problems. Does your car slip in and out of gear? Does it have trouble going up or down steep hills? Maybe you’re having trouble shifting from one gear to another, with shifts coming too soon or too late. If this is happening to you, then you may not have enough hydraulic power. And one of the main causes of a lack of hydraulic power, is your transmission fluid. Just as with unusual noises, the cause may be a lack of transmission fluid, or simply that the fluid is dirty and needs to be flushed. Either of these issues can lead to gear slipping—which makes driving dangerous, and should be looked at and fixed as soon as possible.
- Surging or Stalling. If your car surges forward (or backward), seemingly at random, then it’s a sign that your transmission fluid may have become dirty. Alternately, if your car accelerates too slowly, and seems non-responsive, particularly when the light switches from red to green, this may also indicate a problem with your transmission. Finally, if your car likes to stall when you shift gears, then your transmission fluid may be overburdened with contaminants. In each of these cases, a change in transmission fluid may be necessary. Check the fluid, or have your mechanic take a look.
- The Check Engine or Transmission Warning Light Is On. The Check Engine light may indicate a number of things, but transmission problems are definitely among them. If the Transmission light specifically goes on, that’s an even greater indicator that you may need to replace your fluid. Whatever the problem may be, when a warning light comes on, get it checked out as soon as possible to determine the issue, and have the car serviced.
These are the major signs to look out for when your transmission fluid needs to be changed. If you notice any of them while you’re driving, don’t just let them go. Get them checked out immediately, to determine the problem and get it fixed. Changing transmission fluid is a fairly standard and inexpensive automotive procedure. But the longer you drive with low or dirty fluid, the more damage it will do to your car, and the more serious the repairs will be later on. Get it taken care of now, and save yourself the hassle (and the expense) later on.