WARNING: MAKE SURE THE MAGNETO IS GROUNDED BEFORE INSTALLING THE PROPELLER OR CONNECTING EXTERNAL POWER.
NOTE: McCauley recommends that propeller mounting nuts (if applicable) be replaced at each propeller installation, whenever possible. However, nuts may be reused providing the
threads are in good condition and the locking material prevents turning of the nut on the stud by hand. Propeller mounting bolts must be magnetic particle inspected in accordance with ASTM E-1444 or replaced whenever the propeller is removed from the engine.
NOTE: The aircraft maintenance manual or STC installation instructions should always be consulted for any specialized procedures applicable to a specific aircraft. Various spinner
arrangements not manufactured by McCauley may be used which require additional
(1) Make sure the mating surfaces of the propeller, crankshaft flange, spinner bulkheads, and
spacer, if installed, are clean.
(2) For propeller installations that use a spacer between the propeller and the crankshaft flange and the spacer has been removed from the propeller, do the following:
(a) Make sure the serial number stamped on the spacer is the same as the serial number
stamped on the propeller.
(b) Make sure the alignment dowels are secure in the spacer.
NOTE: If a matched serial number pair of propeller and spacer is not available or if a dowel is loose, the propeller assembly must be taken to an FAA approved Part 145 Propeller Repair Station or international equivalent. If the serial numbers do not match, then the static balance of the propeller is unknown and should not be installed. If a dowel is loose, the dowel will need to be replaced.
(3) Install the spacer and, if applicable, the aft spinner bulkhead on the propeller.
(a) Locate propeller hub on a padded arbor press table, spacer-mating surface face up.
(b) Make sure the serial number on the spacer aligns with the number 1 propeller blade.
NOTE: If the number 1 propeller blade cannot be identified, align the spacer serial
number to the propeller blade with the propeller serial number.
(c) Position the spinner bulkhead, if applicable, on the dowel pins between the propeller and
NOTE: The spinner aft bulkhead must be positioned so that the propeller blades emerge from the bulkhead and spinner with ample clearance. Make sure the felt tip marker line on the spinner aft bulkhead aligns with the mark on the propeller blade.
(d) Apply a film of oil on the dowel pins.
(e) Press the propeller and spacer together with the arbor press. Make sure you do not scratch,
dent or deform the propeller or spacer during this assembly operation.
(4) The assembled propeller, dowel and spacer should be a press fit and not separate easily.
NOTE: When the dowels are in position, the dowels will be engaged approximately half in the spacer or crankshaft flange and half in the propeller hub.
(5) Assembly of the spinner installation is completed as the propeller is installed on the engine
crankshaft flange. Some installations have the spinner aft bulkhead held between the propeller
hub and the spacer. Other installations may have the front bulkhead clamped by the mounting bolts or nuts and the rear bulkhead clamped between the propeller and the crankshaft flange or starter ring gear. Some installations use a spacer support pressed into the front propeller hub bore.
NOTE: The aircraft maintenance manual or STC installation instructions should always be consulted for any specialized procedures applicable to a specific aircraft. Various
spinner arrangements not manufactured by McCauley may be used which require
NOTE: If you have not installed the propeller and spinner assembly on the engine before, the use of a propeller sling and hoist is recommended to prevent accidental damage to
the propeller. If a hoist is not available, the propeller may be supported and lifted by hand. Make sure an adequate number of people are available to support the propeller if a hoist is not used.
(6) Tighten the propeller mounting bolts with the correct torque. The mounting bolt torque for
McCauley fixed pitch propellers is determined by the bolt diameter. Refer to the following table
to determine the correct torque for the propeller mounting bolts.
Bolt or Nut Torque (Dry)
Diameter (Inch) Foot Pounds Inch Pounds N-m
3/8 25 to 35 300 to 360 33.895 to 40.675
7/16 40 to 45 480 to 540 54.233 to 61.012
1/2 55 to 65 660 to 780 74.570 to 88.128
(a) If an adaptor or extension is attached to torque wrench drive end and this adds to the length
of the wrench, then the actual applied torque will be greater than the torque indicated by the wrench reading. The following formula should be used to determine what the torque wrench indicator should read in order to obtain the correct applied torque:
(actual torque required) x (torque wrench length)
-------------------------------------------------------------------=Torque Wrench Reading to Achieve the
(torque wrench length) + (length of the adapter) Required Actual Torque
(7) Torque the mounting bolts/nuts in an alternating sequence to prevent the propeller from rocking on the engine flange.
(8) For propeller mounting bolts with drilled heads, install lockwire (use aminimum diameter of 0.032 corrosion resistant steel conforming to MS20995C32) between pairs of bolt heads.
(9) When shims are required for location of spinner support, select quantity and thickness so that spinner shell screw holes are misaligned with the rear bulkhead holes or nuts by 1/2 hole
diameter. Use at least one mylar shim to contact bolt heads.
(10) When the correct number of shims has been determined, press or lightly tap support into hub bore, apply force to spinner shell toward propeller to align screw holes with bulkhead holes or nuts and install washers and screws.
NOTE: Make sure the felt tip marker line on the spinner aligns with the marker line on the aft