Can also put on a couple drops of Loctite. Both where the
shaft meets the fan, and also to tighten the threads of the
hold down bolt.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Molly Brown" wrote in message
...
Any centrifugal fan that is secured to the fan motor shaft
with only
one bolt will eventually become loose and begin to hit the
fan cage.
This is especially so for fans that are heavy and operated
horizontally. A fan that is hitting its cage will cause the
temperature cut-out to trip and will eventually burn-out.
These types
of fans are usually found in furnaces. It may be possible to
avoid
this by drilling and tapping a second hole perpendicular to
the first
one on the fan for another bolt to better secure it to the
motor shaft
or check to make sure your fan is not secured by only one
bolt before
buying it.