Possible causes of automatic transmission hum when reverse gear is engaged:
1. Wear of friction linings:
* The linings found in the friction packs can wear out over time, causing slipping and humming.
2. Low automatic transmission fluid level:
* Insufficient fluid levels reduce pressure and lubrication, resulting in slipping and humming.
3. Malfunction of the reverse gear control solenoid:
* The solenoid is responsible for engaging reverse gear. Its malfunction can lead to slipping or difficulty engaging the gear.
4. Faulty automatic transmission pump:
* The pump creates pressure in the automatic transmission system. Its malfunction can reduce pressure and cause a hum.
5. Clogged automatic transmission filter:
* A clogged filter restricts the flow of automatic transmission fluid, resulting in low pressure and a humming noise.
6. Worn input or output shafts:
* Worn shafts can cause vibration and hum.
7. Damage to the planetary mechanism:
* The planetary gear may be damaged due to wear or excessive torque, resulting in a humming noise.
8. Incorrect automatic transmission connection:
* Incorrect connection of the automatic transmission to the engine or transmission can lead to slipping and humming.
What to do:
* Check the automatic transmission fluid level.
* Pay attention to any fluid leaks.
* Take the car for diagnostics to a car service to determine the exact cause of the hum.
Consequences of ignoring the automatic transmission hum:
* Exacerbation of automatic transmission damage.
* Slipping or jamming of the automatic transmission.
* Increased fuel consumption.
* Reduced vehicle performance.