How Do I Check if All Wheel Drive Is Working Properly?by Tracy Underwood
All Wheel Drive, or AWD, is a drive system that is commonly installed as an upgrade option in certain passenger cars. This is quite different from the four wheel drive systems in pickup trucks and off-road oriented SUVs in that it incorporates a center differential between the front and rear wheels. This allows all four wheels to receive motive power at all times, while eliminating the binding that occurs when a standard four wheel drive system is activated on dry pavement. If you are considering the purchase of a used AWD vehicle, though, you need to check if the all wheel drive is working properly.
Set the parking brake. Slide the floor jack underneath a structural member in the front of the car. Raise the vehicle until both front wheels just clear the ground.
Lower the jack handle until it sticks straight out in front of the car perpendicular to the ground.
Climb in the car, close the door and start the engine. Release the parking brake. Place the transmission in first gear and momentarily apply a small amount of power. If the AWD system is working correctly, the car will attempt to move forward, propelled by the rear wheels.
Switch the engine off, set the parking brake and get out of the car. Lower and remove the jack. Place the jack under the rear of the car in the same manner as you did the front, with the jack handle pointing straight back.
Climb back in the car and repeat Step three.
Switch off the engine and set the parking brake. Lower and remove the jack.
- If possible, it is best to do this on smooth concrete.
- Make sure the area is clear before you attempt this.
- Do not allow the car to actually move forward, just rock it a little so you can feel it trying to move.
Items you will need
- Floor jack
- "Subaru Owner's Workshop Manual"; Larry Holt, et al; 1988