1996 GMC Sonoma Owner's Manual - Page 70

4LO: This setting also engages your front axle to give you extra traction and provides extra gear reduction. You may never need 4LO. It sends the maximum power to all four wheels. You might choose 4LO if you were driving off-road in sand, mud, or deep snow and climbing or descending steep hills. You can shift from 2HI to 4HI or from 4H1 to 2HI while the vehicle is moving. Do not press the transfer case shift lever button when shifting from 2HI to 4HI or from 4HI to 2HI. Your front axle will engage faster if you take your foot off of the accelerator for afew seconds after you shift. To shift into or out of 4LO: I. The vehicle must be moving less than 3 mph (4.8 km) with the transmission in NEUTRAL (N) for an automatic transmission. For a manual transmission, the clutch pedal must be engaged. The preferred method for shifting into 4LO is to have your vehicle moving 1 to 2 mph (1.6 to 3.2 k d h ) . 2. Press the transfer case shift button and shift in one continuous motion. Don't pause in N SET PARK BRAKE as you shift into or out of 4L0, or your gears could clash. Remember that driving in 4HI or 4LO may reduce fuel economy. Also, driving in four-wheel drive on dry pavement could cause your tires to wear faster and make your transfer case harder to shift and reduce powertrain longevity. To shift your transfer case into N SET PARK BRAKE: 1. Stop the vehicle and shift your transmission into NEUTRAL (N). 2 . Set the parking brake. Your vehicle can roll unless the brakes are applied. 3. Pull the transfer case shift lever into N SET PARK BRAKE. 2-22