Toyota recommends changing the manual transmission fluid in your 1991 Toyota Celica GTS every 30,000 miles (48000km). The fluid lubricates all the gears and the rest of the moving components inside the transmission. Over time, the fluid loses its beneficial properties, hindering proper operation of the gears. Changing your Toyota transmission fluid reqularly not only aids in the functioning of internal components but also extends the service life of your Celica's transmission. With a set of common tools, you can drain and refill the fluid transmission yourself.
Drive your Celica for about 20 minutes so the transmission oil reaches operating temperature.
Park your car on level ground and lift the rear and front of the vehicle with a floor jack and support it with two jack stands at the front and two jack stands at the rear. Make sure the car is stable. This will let you work under the car and level the vehicle so the new transmission fluid is at the correct level.
Locate the filler plug on the left-hand side of the transmission, next to the bell housing. Unfasten the filler plug with a 24 mm box-end wrench. Remove the plug and the gasket underneath. Thoroughly clean the filler hole and filler plug with a lint-free shop rag.
Locate the transmission drain plug toward the rear and bottom right of the case. Place a large drain pan under the drain plug and unfasten the plug with a 24 mm box-end wrench.
Move the drain pan out of the way after draining the oil and wipe clean the area around the drain hole and threads with a lint-free shop rag. Clean the drain plug and threads with the rag as well and replace the plug finger-tight after draining all the oil. Tighten the drain plug with the 24 mm box-end wrench.
Pump 2.5 liters of Dexron III automatic transmission fluid (ATF) through the filler hole using a hand siphon pump. Check the oil level by inserting your finger through the filler hole. The oil should reach the lower edge of the filler hole. Add more oil if necessary.
Replace the filler plug along with a new gasket finger-tight. Tighten the filler plug with the 24 mm box-end wrench.
Lift the rear and front of your Celica with the floor jack, remove the jack stands and lower the car.
Test drive your Toyota.
Check the transmission for oil leaks.
