First, the owner should inspect the transmission fluid for signs of wear. Second, the owner should ensure that the replacement fluid is the correct type for the vehicle. If the fluid is in good condition but the level is low, the owner can add additional fluid. Otherwise, the owner can drain and replace the fluid, which is best done with professional equipment.
Before checking the automatic transmission fluid in a vehicle, the owner can find information on the type of fluid required in the owner's manual. Then, while the engine is at a normal running speed, the owner can locate the gear box and wipe it with a clean cloth to prevent debris from entering.
The owner can then carefully remove the dipstick from the gear box, clean it, and slowly reinsert it. The dipstick will indicate whether the fluid level is low or full. The owner can also check the fluid for signs of wear. If the fluid is darkened or contains dirt or metal, these are signs of a problem that a professional can address.
If the fluid is low, the owner can add fluid using a funnel. It is best to add the fluid slowly to avoid overfilling. To change the fluid completely, the owner must open the plug located on the undercarriage. Placing the vehicle on a lift makes this task much easier. The owner can then drain the fluid into a pan, replace the plug, and refill the gear box with new fluid. Because used transmission fluid is toxic, owners should take it to a mechanic for recycling.