The following factors may have caused the automatic transmission to break down after changing the oil:
Poor quality oil or filter:
* Using the wrong type of transmission fluid or a low quality filter may clog or damage the internal components of the automatic transmission.
Incorrect oil level:
*If the transmission oil level was too low or too high, it could result in insufficient lubrication or excess pressure, which could damage gears, bushings or other components.
Contaminated oil:
*If the transmission fluid used was old or dirty, it could contain particles that could clog oil passages or damage transmission components.
Oil change failure:
* Incorrect oil change procedures, such as handling the oil pan too roughly or damaging the oil pan gasket, could allow contaminants to enter the automatic transmission.
Existing problems with automatic transmission:
* If the automatic transmission already had hidden problems before changing the oil, then changing the oil could aggravate them and lead to breakdown.
Oil change process:
* If any mistakes were made during the oil change process, such as improperly tightening bolts or creating excessive pressure in the system, it could damage the automatic transmission.
Other factors:
* Excessive loads or aggressive driving immediately after an oil change may also contribute to the breakdown.
It is recommended to contact a professional car service to diagnose the automatic transmission and determine the exact cause of the breakdown.