2008 Toyota Tundra Owners Manual - Page 271

07 11.20 (b) A.D.D. (automatic disconnecting differential) The "4LO" (low speed four −wheel drive) indicator light comes on when the "4L" mode is selected. Use this for maximum power and traction. Use "4L" position for climbing or descending steep hills, off −road driving, and hard pulling in sand, mud or deep snow. See "(c) Shifting procedure" for further instructions. In this mode, the vehicle stability control system is off. (See "Vehicle stability control system" on page 250 in this Section.) The A.D.D. can be engaged or disengaged by the shifting operations described in "(c) Shifting procedure". You should drive in four −wheel drive for at least 16 km (10 miles) each month. This will assure that the front drive components are lubricated. (c) Shifting procedure SHIFTING BETWEEN "2WD" AND "4H" To shift from "2WD" to "4H", reduce the vehicle speed to less than 100 km/h (62 mph) and turn the front drive control switch knob fully clockwise. When the ambient temperature is −15_C (5.0_F) or lower, shifting must be performed with the vehicle speed below 70 km/h (43 mph). If the "4HI" (high speed four −wheel drive) indicator light continues to blink when you operate the front drive control switch knob from the "2WD" to the "4H" position, this reminds you that the transfer mode is not securely in "4H" mode. Drive straight ahead while accelerating or decelerating. If the "4HI" (high speed four −wheel drive) indicator light continues to blink and the buzzer sounds when you operate the front drive control switch knob from the "2WD" to the "4H" position, this reminds you that the transfer mode is not in "4H" mode. Stop the vehicle or reduce the vehicle speed to less than 100 km/h (62 mph). (When the ambient temperature is −15_C (5.0_F) or lower, speed needs to be reduced to below 70 km/h (43 mph).) Operate the switch knob again. 241 2008 TUNDRA from Apr. '08 Prod. (OM34477U)