This article is from the Toyota Tundra FAQ, by Steve Yee with numerous contributions by others.
You should use your 4x4 system at least 10 miles every month. This insures
that all lubricants and fluids are distributed properly and your 4x4 system is
kept in a working order.
Note: Be sure that you do NOT use your 4x4 system on dry pavement !
 
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