LX50 focus knob problems

When focusing, I feel that the focus knob is a little loose (or
"lags"), that is it takes a turn before it respones. So when I focus at
one direction, and then try to focus to the other direction it takes a
while before it starts to focus. I assume that it is a little loose.
What should I do to fix this?
The telescope is a Meade LX-50 10".

Thanks in advance.