Shocks when shifting gears in an automatic transmission can occur for several reasons:
Insufficient fluid pressure:
*Low transmission fluid level
* Oil pump malfunction
* Oil filter clogged
Faulty solenoids:
* Solenoids are responsible for shifting gears. Failure to do so can result in incorrect fluid pressure and jerking.
Worn clutches:
* Clutches are used to transmit torque. Their wear can cause slippage when shifting gears.
Faulty torque converter:
* The torque converter smoothes the transition between gears. If it malfunctions, it can cause shock and vibration.
Electronics problems:
* Faulty sensors or electronic control unit (ECU) may send incorrect signals, resulting in shifting problems.
Other possible reasons:
* Worn engine or transmission mounts
* Faulty driveshaft
* Damage to gears or gear teeth
How to fix:
* Check the level and condition of the transmission fluid.
* Diagnose and, if necessary, replace faulty solenoids, clutches or torque converter.
* Check the condition of the electronics, including sensors and ECU.
* Fix problems with bearings or driveshaft.
* Repair or replace damaged gears.