Possible reasons for the automatic transmission jerking when the speed decreases:
1. Torque converter malfunction:
* Worn friction discs
* Faulty pump
*Transmission fluid level too low
2. Problems with electronic control:
* Faulty speed sensor
* Faulty solenoid
* Transmission ECU malfunction
3. Mechanical problems:
* Worn or damaged gears or bearings
* Broken or weakened return springs
* Faulty gear selector
4. Shift cable fault:
* Worn or stretched cable
* Poor cable adjustment
5. Problems with transmission fluid (ATF):
* Insufficient fluid level
* Contaminated or old fluid
* Incorrect ATF type
Diagnosis of the problem:
* Checking the level and condition of the transmission fluid
* Scan Trouble Codes (DTC)
* Test drive with connected data scanner
* Diagnostics of the automatic transmission hydraulic system
Ways to fix the problem:
* Replacement of transmission fluid and filter
* Diagnostics and repair of faulty components (torque converter, solenoids, sensors)
*Adjusting or replacing shift cable
* Repair of mechanical faults in the gearbox
Important:
* A jerking transmission may be a sign of a serious problem that requires immediate attention.
* Ignoring this problem may result in further damage and costly repairs.
* It is strongly recommended that you contact a qualified mechanic for automatic transmission diagnosis and repair.