What are the implications of foamy transmission fluid in a 1996 Chevrolet Suburban 1500?

Answer 1

If the fluid is full of bubbles or is foamy, the transmission is probably overfilled with ATF. Other causes include using the wrong type of ATF or a plugged transmission vent. If the fluid level is too high, the fluid can become mixed with air (aerated) causing shifting problems, slippage and noise. A real no, no, is to overfill a transmission. Check the level when the transmission is hot, on level ground. On most vehicles this is done with the engine idling and the transmission in Park. Check your owners manual for the proper procedure on your Suburban. Moving the gear selector thorough each gear position prior to checking the level will help assure an accurate reading. The fact that the fluid is foamy, may prevent you from getting an accurate reading. If so, then I would suggest you drain enough fluid out to be able to read the level accurately. Your transmission uses Dexron 3 fluid. If any other fluid has been added or you suspect the wrong fluid has been added, have a complete fluid change and flush performed. Otherwise you may end up destroying your transmission.