Clunking Noise When Shifting Into Gear (Automatic)

On an automatic transmission, the common cause for "clunking" is an incorrect level of transmission fluid. A transmission is a complex set of hydraulic parts and when the level of fluid is either too low or too high, a clunking noise may result.

1. Check the transmission fluid.
On most vehicles, the transmission fluid is checked "hot," or while the car is running. Begin by turning on your vehicle and let it run for a minute while you locate the transmission dipstick. After you have located the dipstick, remove it and wipe it clean with a rag.

Notice the markings and reinsert it fully. Remove the dipstick again, and check the level of the fluid. If the fluid is low, transmission fluid will need to be added. If it is high, you can drain the additional fluid according to your manufacturer's instructions. (On most vehicles, transmission fluid is added directly to the tube from which you removed the dipstick. Use a narrow funnel and add only enough fluid to raise the level to full. )

If the fluid level was incorrect, you should have solved the problem. If the fluid level was within the "normal" range, proceed to step two.

2. Bigger Problems
If your auto wan't just high or low on fluid, you may be facing a slightly more burdensome problem -- usually bad driveline joints or motor mounts.

A common problem that causes a "clunk" noise is bad driveline jopints. The CV joints (FWD) or the U-Joint (RWD) of the vehicle can become worn and make this noise when the car is shifted from park to drive. The transfer of torque may cause the noise you have noticed.

Engine or motor mounts hold your engine to the frame and they must be secure to avoid the clunking noise. When you shift your car into gear the torque from the engine is transferred and anything that is loose may make a loud clunking noise.