1997 Mercury Mountaineer Four Wheeling Supplement 1st Printing - Page 4

4WD and AWD systems drive over terrain and road conditions that a conventional two-wheel drive vehicle can't. Power is supplied to all four wheels through a transfer case. On 4WD vehicles the transfer case allows you to select 4WD when necessary. Information on transfer case operation, shifting procedures and maintenance can be found in your "Owner's Guide." You should become thoroughly familiar with this information before you operate your vehicle. Normal characteristics • On some 4WD models, the initial shift from two-wheel drive to 4x4 while the vehicle is moving can cause some momentary clunk and ratcheting sounds. This is the front drivetrain coming up to speed and the automatic locking hubs engaging and is not cause for concern. • On some 4WD models, if the vehicle is stopped while in 4WD and the vehicle direction is reversed from the previous direction, the automatic locking hubs will momentarily disengage and re-engage. The automatic locking hubs may click as they automatically engage in the new direction. 4