Reasons for automatic transmission slipping when changing gears:
Low transmission fluid level:
* Insufficient lubrication will cause overheating and damage to the transmission.
Contaminated or poor quality transmission fluid:
* Contaminants can clog hydraulic passages and reduce fluid pressure.
Worn or damaged control solenoid:
* Solenoids regulate fluid flow, responsible for smooth gear shifting.
Clogged or restricted transmission filter:
* A clogged filter prevents proper fluid flow.
Worn or damaged clutches:
* Frictions (clutches) transfer power from the engine to the transmission. Their wear leads to slippage.
Blocked or stuck hydraulic passages:
* Blockages or deposits can block the passages, reducing fluid pressure.
Faulty input or output shaft speed sensor:
* Incorrect speed information results in incorrect gear shifting.
Worn or damaged torque transformer:
* The torque transformer transfers power from the engine to the transmission. Wear or damage may result in slippage.
Other possible reasons:
* Malfunction of the electronic control unit (ECU)
*Damage or wear of gears
* Deformation of the transmission housing
* High load on the transmission (for example, towing a heavy load)