Shocks when engaging the reverse gear of the automatic transmission can be caused by the following reasons:
Hydraulic problems:
*Low or contaminated transmission fluid
*Faulty oil pump or shift solenoid
* Valve block clogged
Mechanical problems:
* Worn or damaged reverse brake band
* Worn or damaged planetary gear
* Faulty differential
Electrical problems:
* Faulty transmission position sensor
* Faulty Transmission Control Unit (TCU)
*Wiring problems
Other possible reasons:
*Poor transmission or engine mounting
* Worn or damaged transmission mounts
* Incorrect tire pressure (over or under pressure)
Solution:
To diagnose and eliminate shocks when the automatic transmission is engaged in reverse gear, you must perform the following steps:
* Check transmission fluid level and condition: Low or contaminated fluid levels can cause slippage and knocking.
* Check trouble codes: The TCU may store fault codes that can help determine the cause of the knocks.
* Perform a visual inspection: Check for leaks, damage and signs of wear.
* Perform a Pressure Test: Check the transmission system pressure to determine if it is within specifications.
* Inspect the valve body: Remove and inspect the valve body for signs of blockage or damage.
* Replace faulty components: If faulty components are found, such as the brake band, planetary gear, or shift solenoid, they must be replaced.
Warning: Automatic transmission repairs can be complex and expensive. It is always recommended to take it to a qualified mechanic for diagnosis and repair.