Possible causes of automatic transmission jerking when shifting gears on a Ford Focus:
* Low or contaminated transmission fluid: Check the level and condition of the transmission fluid and replace it if necessary.
* Clogged or faulty automatic transmission filter: Replace the automatic transmission filter, as a clogged filter may restrict fluid flow.
* Worn or damaged friction plates: The friction plates in an automatic transmission can become worn or damaged over time, resulting in jerky gear changes.
* Faulty automatic transmission solenoids: The solenoids control the flow of fluid into the automatic transmission, and their failure can cause jerking when shifting gears.
* Worn automatic transmission oil pump: The oil pump supplies automatic transmission fluid under pressure, and wear can reduce pressure and cause jerking when shifting gears.
* Faulty electronic transmission control module (TCM): The TCM controls the operation of the automatic transmission, and a malfunction can cause problems with shifting gears.
*Automatic Transmission Wiring Problems: Faulty electrical wiring can interfere with the operation of the solenoids and other automatic transmission components, resulting in jerky shifts.
* Problems with automatic transmission mechanical components: In some cases, there are problems with automatic transmission mechanical components such as gears,??? differential, can cause jerking when changing gears.
Troubleshooting steps:
1. Check the level and condition of the automatic transmission fluid.
2. Make sure that the automatic transmission filter is not clogged or damaged.
3. Scan the vehicle for automatic transmission related fault codes.
4. Have the automatic transmission diagnosed and repaired by a qualified mechanic.