Possible causes of clunking noise when changing gears in an automatic transmission:
1. Low transmission fluid level
* Low fluid levels can lead to oil starvation and overheating of the internal components of the automatic transmission, causing clunking noises.
2. Contaminated transmission fluid
* Dirty fluid may contain metal, debris, or other contaminants that can block the hydraulic passages and cause slipping or clunking.
3. Worn or damaged internal components
* Worn or damaged gears, clutches, torque converter or other internal components may cause clunking noises when shifting gears.
4. Electrical problems
* Faulty sensors or solenoids can send incorrect signals to the automatic transmission control unit, resulting in incorrect shifting and clunking noises.
5. Faulty hydraulic unit
* The hydraulic unit is responsible for the fluid pressure in the automatic transmission. If it is faulty, it can result in insufficient pressure, resulting in clunking noises when shifting gears.
6. Worn or damaged engine or transmission mounts
* Worn or damaged mounts can cause shudder or vibration in the engine or transmission, which can be transmitted to the automatic transmission and cause a clunking noise.
7. Faulty torque converter
* The torque converter transfers power from the engine to the automatic transmission. If it is faulty, it can cause slipping or clunking when shifting gears.
8. Fluid compatibility
*If the automatic transmission is filled with inappropriate transmission fluid, it may cause slipping, clunking, or other shifting problems.
Diagnostics:
For an accurate diagnosis, inspection and diagnosis must be performed by a qualified mechanic. They can use a trouble code scanner to check fluid levels, pressure, and other components to determine the root cause of the clunking noise.