Here's what the manual says:
Do not use 4H (4X4) or 4L (4X4 LOW) on dry, hard surfaced roads.
Doing so will produce excessive noise, increased tire wear and may
damage drive components. 4H (4X4) and 4L (4X4 LOW) are only
intended for consistently slippery or loose surfaces. Use of 4H (4X4) or
4L (4X4 LOW) on these surfaces may produce some noise (such as
occasional clunks) but will not damage drive components
-- Chuck