Possible reasons:
1. Low level or contamination of transmission fluid:
* Check the fluid level and condition.
* Replace fluid if necessary.
2. Malfunction of solenoids:
* These solenoid valves control the flow of fluid in the transmission.
* Their malfunction can lead to gear slipping and jolting.
3. Worn friction discs:
*Over time, these discs wear out and may cause slipping or delays when shifting.
4. Problems with the torque converter:
* The torque converter transfers power from the engine to the transmission.
* Failure to do so may result in slipping and jolting.
5. Electrical problems:
* Faulty wiring or sensors may interfere with signals to the transmission control module, resulting in incorrect shifts.
6. Worn bearings or gears:
*Excessive wear can result in vibration and noise during gear shifting.
7. Problems with programming:
*Modern transmissions have sophisticated electronics.
*Programming errors may result in incorrect operation.
Possible solutions:
* Check the level and condition of the transmission fluid and replace it if necessary.
* Identify and replace faulty solenoids.
* Have your vehicle overhauled to replace worn discs or other components.
* Scan the vehicle for transmission related trouble codes.
*Update transmission software if necessary.
*Consult a qualified automatic transmission mechanic.