Possible causes of shocks when shifting gears in a Volvo automatic transmission:
1. Low transmission fluid level:
* Lack of fluid leads to a decrease in pressure in the system, which causes slipping and shocks when switching.
2. Contaminated or old transmission fluid:
* Dirty fluid may contain abrasive particles that can damage the internal components of the automatic transmission and cause shocks.
3. Faulty solenoid coil:
*Solenoid coils are responsible for regulating the flow of transmission fluid. A faulty coil can cause fluid flow problems and lead to shocks.
4. Valve body problems:
* The valve body directs transmission fluid to the correct passages. A faulty valve body can result in improper fluid distribution and cause shock.
5. Worn friction discs:
* Friction discs transfer power from the engine to the transmission. Worn discs can slip, causing shifting noise.
6. Faulty torque converter:
* The torque converter transfers torque from the engine to the transmission. A faulty torque converter can cause vibrations and shocks when shifting.
7. Faulty gear selector position sensor:
* The gear selector position sensor tells the automatic transmission what position the gear shift lever is in. A faulty sensor can cause shifting confusion and jerking.
8. Problems with the electronic control unit (ECU):
* The ECU controls the operation of the automatic transmission. A faulty ECU can cause the transmission to malfunction and cause vibrations.
Recommended actions:
* Check the transmission fluid level.
* Replace transmission fluid and filter if necessary.
* Diagnose and if necessary replace faulty solenoid coils, valve body, friction discs or torque converter.
* Check the gear selector position sensor and replace it if necessary.
* Connect the vehicle to a diagnostic scan tool to check for trouble codes that may indicate ECU problems.