What must be done with the transfer case before flat towing an automatic transmission?

Before flat towing a vehicle with an automatic transmission, it is essential to shift the transfer case into PARK. This is necessary because in this position, the transmission is locked against output rotation, preventing any potential damage to the transmission and ensuring that the vehicle remains stationary during towing.

When a vehicle is flat towed, the drive wheels are in contact with the ground, and without putting the transmission in PARK, the drivetrain components could potentially rotate, which may lead to transmission fluid not circulating properly and resulting in severe damage. Engaging PARK avoids these risks and preserves the integrity of the transmission system during the tow.

Other positions, such as DRIVE or reverse, would not secure the drivetrain and could allow for unwanted movement, leading to complications or damage while towing. Engaging 4WD is not essential for all vehicles being flat towed and varies by vehicle specifications, making PARK the clear choice for safeguarding the automatic transmission during the towing process.