Grinding or Shaking
Depending on whether you have a manual or automatic transmission, your car may respond differently when your transmission isn't working correctly. As noted in a previous section, with a manual transmission, a common sign of trouble is a grinding sound or feeling when you shift into a new gear. If you fully engage the clutch, shift and then hear a grinding sound, you may have a worn clutch or you may just need to have it adjusted [source: AAMCO]. Or perhaps one or more of your transmission's gear synchronizers, or synchros, is worn out or damaged. Grinding gears can be caused by a number of different factors.
For automatic transmissions problems, you'll most likely feel the car shimmy into each gear rather than the typical almost unnoticeable shifts, or the transmission will make a jarring transition into the next gear. Both are signs that your transmission needs attention. If you notice anything other than a smooth transition between gears, then you might need to have your automatic transmission looked at for adjustments or repair.
But feeling transmission problems aren't the only way to use your senses. Go on to the next page to see what sounds you should be listening for as well.