* Automatic Transmission: The fill location is usually on the transmission itself, often a small dipstick with markings, similar to engine oil. However, some 1991 Blazers may require filling through a separate fill port on the side or top of the transmission. You *cannot* rely solely on a dipstick, as some only check fluid level, not allow for filling. Consult your owner's manual for the specific location and procedure. If you don't have the manual, look carefully around the transmission case for a plug with a fill port.
* Manual Transmission: Manual transmissions generally don't have a dipstick; they are filled through a separate fill plug on the transmission case. Again, your owner's manual will show the correct location.
Crucially: Before attempting to add transmission fluid, locate your owner's manual to find the specific fill location and the correct type of transmission fluid to use for your vehicle. Using the wrong fluid can damage your transmission. If you don't have the manual, a reliable online resource like a parts store website (e.g., AutoZone, Advance Auto Parts) with your vehicle's VIN can be helpful.
