Possible causes of jerking when engaging reverse gear on an automatic transmission:
Mechanical problems:
* Faulty torque converter solenoid
* Worn reverse gear clutches
*Transmission fluid leak
*Low transmission fluid level
* Contaminated or old transmission fluid
*Broken transmission wiring harness
Electrical problems:
* Faulty gear selector position sensor
*Faulty Transmission Control Module (TCM)
Hydraulic problems:
* Clogged valve body
* Worn torque converter
Software problems:
* Incorrect TCM software
Troubleshooting steps:
1. Check the transmission fluid level and condition: Make sure the transmission fluid level is correct and that the fluid is not dirty or has a burning odor.
2. Diagnose with a scan tool: Use a diagnostic scanner to look for trouble codes indicating problems with the transmission or TCM.
3. Check Wiring: Visually inspect the transmission wiring harness for damage or connectors that are not fully connected.
4. Check Solenoids: Using an oscilloscope, check that the torque converter solenoid is operating properly.
5. Inspect the Reverse Package: During a transmission overhaul, inspect the friction discs, steel plates, and reverse package seals for wear or damage.
6. Flush the valve body: Clean the transmission valve body with solvent to remove any contaminants or particles that may be obstructing fluid flow.
7. Update Software: If you suspect a software problem, contact your dealer or authorized workshop to update the TCM software.
If the jerking when engaging reverse gear continues, the transmission may require major repairs or replacement. Contact a qualified mechanic for accurate diagnosis and repair.