Possible reasons for the automatic transmission sticking when shifting gears:
1. Lack of transmission fluid (ATF)
*Low ATF levels can result in insufficient pressure and difficult shifting.
2. Dirty or worn transmission fluid
* Contaminated ATF may contain debris or metal shavings that can block valves and cause sticking.
3. Solenoid failure
* The solenoids that control gear shifting may fail or operate incorrectly, causing difficulty shifting from one gear to another.
4. Problems with the torque converter
* The torque converter transfers torque from the engine to the transmission. If it is damaged or worn, it can cause slipping or sticking when shifting.
5. Wear of brake bands and clutch discs
*Brake bands and clutch discs in the transmission can wear out over time, causing slipping or sticking when shifting.
6. Electrical problems
*A damaged or loose wire can cut off power to the transmission, which can cause shifting problems.
7. Software glitches
*Computer controlled transmissions may experience software glitches that affect their performance.
8. Mechanical damage
*Physical damage to gears, bearings or other transmission components can cause binding or failure.
Troubleshooting steps:
* Check the level and condition of the transmission fluid.
* Replace transmission fluid and filter if necessary.
* Diagnose and repair or replace faulty solenoids.
* Check and repair the torque converter if necessary.
* Replace worn brake bands and clutch discs.
*Repair any electrical problems.
*Update transmission software if necessary.
* If there is mechanical damage, contact a mechanic for repair or replacement.
Important:
A stuck automatic transmission can cause more serious damage if not corrected. If you are experiencing problems with your gear shifting, it is recommended that you contact an experienced auto mechanic for diagnosis and repair as soon as possible.