How to Troubleshoot a General Motors Automatic Transmission
- 1). Check for a transmission fluid leak underneath your vehicle. This is identifiable as reddish, oily fluid. If your transmission is leaking fluid, you may have a cracked or defective pan gasket, a loose filler tube or extension housing to the transmission case, or a converter housing area leakage. Leaks may also be caused by an overflow from the oil filler tube.
- 2). Check your transmission fluid to see if it smells burnt, as this is a sign of automatic transmission overheating. This is caused by low fluid levels, a clogged fluid cooler line, a faulty oil pump or slippage.
- 3). Listen for buzzing or whirling noises. These noises are caused by low fluid levels, scored gears or even a faulty torque converter.
- 4). Check to see if your transmission slips when transitioning gears, or if your transmission does not change gears at all. While low fluid levels can cause these problems, it is more likely that your transmission has a defective vacuum linkage control or broken vacuum line, failed internal clutch or bands or other internal mechanical failure.
