Hartzell HC-D2MV20-3 Series Owner's Manual And Logbook page 130

(4) Adjusting Travel on Hydraulic Unit With Governor
(a) Pull the piston out with the propeller counterweights,
until the piston guide arms extend a maximum of 0.50
inch (12.7 mm) for a 0.125 inch (3.17 mm) diaphragm
from the outer diaphragm ring B-120.
(b) On Lycoming engines, the clearance between the jack
plate and any portion of the hub or spinner ring should
be no less than 0.063 inch (1.59 mm) and no greater
than 0.125 inch (3.17 mm). On Continental engines,
the clearance between the jack plate and any portion
of the hub or spinner ring should be exactly 0.125
inch (3.17 mm).
NOTE:
(c) The spool should extend 1.31 inches (33.3 mm)
beyond the valve casting.
NOTE:
(d) Pull the cockpit propeller control into full high pitch
and force the piston back to check for washers,
screws, or safety wire that may prevent the piston
guide arms from touching the outer diaphragm ring
B-120 or high pitch position.
INSTALLATION AND REMOVAL
Propeller Owner's Manual
Adjust the spacers behind the rear cone to
obtain the applicable clearance; however,
never allow the hub nut to engage less
than five full threads. Restrict the travel to
maintain this clearance.
To obtain the proper dimension, remove the
link, grip the small end in a vise, and bend it
until the distance between the two holes on
the link has changed the required amount
to obtain 1.31 inches (33.3 mm) on the
spool length.
140
61-00-40
Page 3-64
Nov/02