Navaid devices servo

[Miles McCallum <milesm@avnet.co.uk>]

In the process of installing my Navaid devices servo, and somewhat disconcerted
to find
that it feels somewhat gritty, particularly over about 60% of the travel - there
doesn't
seem to be any method of adjusting the clearance between the last two gears, 
which
is
where the problem obviously lies.

Anyone else had this problem, and come up with any solutions (other than sending
it
back).......?

Miles