This article is from the Toyota Tundra FAQ, by Steve Yee with numerous contributions by others.
Some 2000 model year Tundra owners have reported problems with their 4x4
Tundras not going into 4-Lo and hearing a grinding sound when that happens.
The solution is a mis-machined shaft in the front servo assembly and another
mis-machined shaft in the transfer case. Many owners have had to have their
actuator rods replaced per Toyota Engineering. Others have requested that
their entire Transfer Case be replaced. In either case, owners have reported a
downtime of roughly two weeks without their Tundra.
This problem may not be recognized by most Toyota tech staffs and their support
system. Most owners who have had this problem have had to require the
dealership contact Toyota Engineering directly for the fix.
 
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