Toyota 2000 Tundra Owner's Manual page 105

See "(c) Shifting procedure (button type)"
for further instructions.
(b) A.D.D. (automatic
disconnecting differential)
Type A
Type B
TUNDRA (34413U)
The A.D.D. can be engaged or disen-
gaged by the shifting operations de-
scribed 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 com-
ponents are lubricated.
103