Transmission oil is necessary in a Chevy equipped with a Duramax diesel engine to keep the gears inside the transmission running smoothly and to help prevent them from grinding or becoming damaged due to excessive heat. Like the Chevy's engine, the transmission needs oil to lubricate all of the internal components. Periodically, you may need to check and add oil to the transmission. But to do this, you'll need to understand how to add transmission oil to your Chevy.
Open the hood of the Chevy and locate the transmission dipstick. It will normally be located in the rear of the engine bay.
Pull the dipstick out and wipe it off with a clean rag.
Re-insert the dipstick and then pull it out once more. Check the fluid level on the dipstick. There will be two marks on the tip of the dipstick. The fluid should be between the upper and lower marks on the dipstick. If the fluid is below the lower mark, you'll need to add more fluid.
Place the narrow end of the funnel into the opening where the dipstick normally goes.
Pour transmission fluid approved for Chevy transmissions into the funnel. Periodically repeat steps 2 and 3 to make sure that you do not fill the transmission above the upper mark on the dipstick.
