Low transmission fluid is a common cause of clunking sounds in automatic transmissions. Because a transmission needs to be filled to the proper level in order to operate correctly, inadequate lubrication can lead to gears that are not properly engaged and worn transmission components.
Bent or Broken Transmission Shift Fork
A transmission shift fork is a component in an automatic transmission that moves the transmission into different gears. When a shift fork is bent or broken, the transmission may not properly shift into gear, resulting in a clunking sound.
Damaged Transmission Gears
Damaged transmission gears can also cause clunking sounds. Transmission gears can become damaged due to several factors, such as improper maintenance, excessive wear, and overheating.
Worn Transmission Mounts
Worn transmission mounts can allow too much movement in the transmission, which can cause a clunking sound as the transmission shifts into gear.
Driveline Problems
Other driveline components like U-joints, driveshafts, or CV axles can also cause clunking sounds that you may mistake for transmission problems.
