Causes of automatic transmission vibration at idle
*Faulty torque converter: Damaged torque converter blades or gears can cause uneven fluid flow, resulting in vibration.
* Torque Converter Slip: This occurs when the torque converter is unable to efficiently transfer power from the engine to the transmission, causing slipping and vibration.
*Worn Bearings: Worn or damaged bearings in the transmission can cause vibration due to misalignment of the rotating components.
*Low Automatic Transmission Fluid Level: Insufficient fluid level can result in insufficient pressure, which causes slippage and vibration.
* Contaminated transmission fluid: Contaminated transmission fluid contains abrasive particles that can damage transmission components and cause vibration.
* Worn Flywheel: Worn flywheel teeth can cause uneven engagement with the starter, resulting in vibration.
* Engine Problems: Faulty spark plugs, ignition coils, or leaking intake/exhaust valves can cause engine vibration that is transmitted to the transmission.
* Faulty engine or transmission mounts: Loose or damaged mounts can allow the engine or transmission to move and create vibration.
Diagnostics
To diagnose the source of vibration, follow these steps:
* Check the level and condition of the automatic transmission fluid.
* Scan for transmission related trouble codes.
* Inspect the torque converter, bearings and other internal transmission components (if possible).
* Check the flywheel for wear.
* Check engine and transmission mounts for looseness or damage.
Solution
The solution to the problem of automatic transmission vibration at idle depends on the source of the malfunction:
* Replace the faulty torque converter.
* Repair or replace the slipping torque converter.
* Replace worn bearings.
* Add or replace automatic transmission fluid.
* Replace contaminated automatic transmission fluid.
* Replace worn flywheel.
* Solve engine problems.
* Tighten or replace loose or damaged fasteners.
If the vibration is severe or is accompanied by other symptoms such as transmission slipping or fluid leakage, it is recommended that you contact a qualified mechanic immediately.