1997 GMC Suburban Owner's Manual - Page 305

Add fluid only after checking the transmission fluid HOT. (A COLD check is used only as a reference.) If the fluid level is low, add only enough of the proper fluid to bring the level up to the HOT area for a hot check. It doesn't take much fluid, generally less than one pint (0.5 L). Dun 't ove$lZ. r NOTICE: We recommend you use only fluid labeled is DEXRON@-111, because fluid with that label made especiallyfor your automatic transmission. Damage caused by fluid other than DEXRON-I11 is not covered by your new vehicle warranty. 3. Check both sides of the dipstick, and read the lower level. The fluid level must be in the COLD area for a cold check or in the HOT area or cross-hatchedarea for a hot check. 4. If the fluid level is in the acceptable range, push the dipstick back in all the way; then flip the handle down to lock the dipstick in place. 0 After adding fluid, recheck the fluid level as described under "How to Check." When the correct fluid level is obtained, push the dipstick back in all the way; then flip the handle down to lock the dipstick in place. How to Add Fluid Refer to the Maintenance Schedule to determine what kind of transmission fluid touse. See "Recommended Fluids and Lubricants" in the Index. 0 6-23