The transmission in your car is a complicated set of gears that transfers the energy of the engine to the wheels. The transmission will give you warning signs when there is a problem and, if you ignore them, you'll find yourself in a car that won't go anywhere. Here are some of the common ways that your transmission tells you there is a problem.
1. There is a delay when shifting gears.
Your car should shift smoothly through all of the gears. If it hesitates briefly before moving into one or more gears, get your car in for an inspection of the transmission. There could be a transmission fluid leak resulting in low levels of lubrication or a problem with the computer shifting module.
2. There is a metallic sound when shifting gears.
If you hear a "clunk" when the car changes gears, the transmission may be having difficulty synchronizing the gears as it shifts. There could be grit in the transmission that prevents the gears from meshing correctly. You may need to have the transmission box flushed out and refilled with fresh fluid.
3. The car repeatedly slips in and out of gears.
If you're driving on a level road and you notice the car slipping in and out of its gears, you could have a low transmission fluid level. Or it could be a more serious problem and the device that keeps the transmission in one gear at a time is worn out. Get your car in quickly for an inspection to prevent further damage to the transmission in case there is a major component failure.
4. The car makes a rattling noise from the transmission when in neutral.
When idling with the car in "Park," your transmission should make no noise at all. Any sound from the transmission when the car is sitting still can mean something is broken or loose in the transmission. You need to get the car in right away to diagnose the problem as a loose piece can jam the gears while driving.
5. The transmission fluid is low.
If you take your car in for a tune up and the technician says that your transmission fluid level is low, look for a leak. Transmission fluid doesn't break down like the oil in your engine. The only way the level can go down is by the fluid escaping through a faulty seal or a crack in the transmission case. Look under the car where you normally park at home or work for a thick, reddish liquid, which is the transmission fluid.