GM Service Manual Online
For 1990-2009 cars only

If your vehicle has four-wheel drive, you can send your engine's driving power to all four wheels for extra traction. To shift out of two-wheel drive and into four-wheel drive, move the transfer case shift lever to FOUR-WHEEL HIGH (4H) or FOUR-WHEEL LOW (4L). You should use TWO-WHEEL HIGH (2H) for most normal driving. See "Transfer Case" following.

Notice: Driving on pavement in four-wheel drive for an extended period of time may cause premature wear on your vehicle's powertrain. Do not drive in four-wheel drive on pavement for extended periods of time.

Transfer Case


Object Number: 810125  Size: B3

The transfer case shift lever is on the floor to the right of the driver. Use this lever to shift into and out of four-wheel drive. An indicator light comes on when the transfer case is in four-wheel drive.

Your vehicle's transfer case shift lever may shake or vibrate. This is normal and your vehicle does not require service.

TWO-WHEEL HIGH (2H): This setting is for driving in most street and highway situations. Your front axle is not engaged in two-wheel drive.

FOUR-WHEEL HIGH (4H): This setting engages your front axle to help drive your vehicle. Use FOUR-WHEEL HIGH (4H) when you need extra traction, such as on wet or icy roads, or in most off-road situations.

NEUTRAL (N): Shift to this setting only when your vehicle needs to be towed.

Caution: Shifting the transfer case to Neutral can cause the vehicle to roll even if the transmission is in P (Park), or if you have a manual transmission, even if you are in gear. You or someone else could be seriously injured. Be sure to set the parking brake before placing the transfer case in Neutral. See Parking Brake.

FOUR-WHEEL LOW (4L): This setting also engages your front axle to give you extra traction and can be used for driving downhill, uphill or on rocky terrain when you're driving slower than 35 mph (55 km/h).

Remember that driving in FOUR-WHEEL HIGH (4H) or FOUR-WHEEL LOW (4L) 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.

You can shift from TWO-WHEEL HIGH (2H) to FOUR-WHEEL HIGH (4H) or from FOUR-WHEEL HIGH (4H) to TWO-WHEEL HIGH (2H) at any speed if your vehicle is going less than 60 mph (100 km/h) and your wheels are straight ahead . Your front axle will engage faster if you take your foot off the accelerator pedal for a few seconds as you shift.

Shifting Into or Out of FOUR-WHEEL LOW (4L)

  1. Stop your vehicle and shift your transmission to NEUTRAL (N).
  2. Shift the transfer case in one continuous motion.

Don't pause in NEUTRAL (N) as you shift from FOUR-WHEEL LOW (4L) to FOUR-WHEEL HIGH (4H), or your gears could clash.