Symptoms of a broken automatic transmission:
Slip:
* Gear slipping during acceleration or going uphill.
* Increasing engine speed without a corresponding increase in speed.
Knock or Rumble:
* A loud knocking sound is heard when shifting gears.
* Humming or rumbling noise when driving.
Start-up or gear shift delay:
* The transmission changes gears slowly.
* It feels like the gearbox is “sticking” in one gear.
No movement:
* The vehicle does not move forward or backward even though the transmission is in gear.
Extraneous noise:
* Vibration or shaking when shifting gears.
* Howling or squeaking sound while driving.
Fluid leak:
* Red fluid is leaking from the gearbox.
* Transmission fluid level is low.
Burning smell:
* Burnt oil or rubber smell coming from the gearbox.
Check Engine:
* The Check Engine light on the dashboard comes on.
* Engine management fault codes related to the transmission.
Other possible symptoms:
* Difficulty shifting gears.
* Forced transmission shutdown.
* Problems with shifting gears into park.
* Inability to change gear from Park.