1994 GMC Safari Owner's Manual - Page 239

NOTICE: Too much or too little fluid can damage your transmission. Too much can mean that some of the fluid could come out and fall on hot engine parts or exhaust system, starting Be sure to get a fire. an accurate reading you check your transmission fluid. if Wait atleast 30 minutes before checking the transmission fluid level if you have been driving: When outside temperatures are above 90"F (32°C). At high speed for quite a while. In heavy traffic - especially in hot weather. While pulling a trailer. To get the right reading, the fluid should be at normal operating temperature, which is 180°F to 200°F (82°Cto 93°C). To check transmissionfluid hot: Get the vehicle warmed up bydriving about 15 miles (24 km) when outside temperatures are above 50°F (10°C). If it's colder than 50°F (1 O"C), drive the vehicle in "D" (3rd Gear) until the engine temperature gage moves and then remains steady for ten minutes. Then follow the hot check procedures. To check transmissionfluid cold: A cold check is made after the vehicle has been sitting for eight hours or more with the engine off and is used only as a reference. Let the engine run at idle for fiveminutes if outside temperatures are 50°F (10°C) ormore. If it's colder than 50°F ( 10°C), you may have to idle the engine longer. Should the fluid level be low during a cold check, you must perform a hot check before adding fluid. This will give you a more accurate reading of the fluid level. To check the fluid hot cold or Park your vehicle on a level place. With the parking brake applied, place the shift lever in "P" (Park). With your foot on the brake pedal, move the shift lever through each gear range, pausing for about three seconds in each range. Then, position the shift lever in "P" (Park). Let the engine run at idle for three minutes or more. 6-21