16G1-146-3 PN 177370-2.pdf

T.O. 16G1-146-3

TECHNICAL MANUAL

OVERHAUL INSTRUCTIONS

NOSE LANDING GEAR DOOR

90 DEGREE GEARBOX ASSEMBLY

PART NUMBER NSN

177370 1680-00-220-2810

177370-1 1680-00-298-8782

177370-2 1680-01-159-9590

CEI NO. MA0001A

DETAIL SPEC NO. 41669

(ATOS)

(CURTISS-WRIGHT FLIGHT SYSTEMS)

(71791)

AF33(657)-15053

F41608-82-G-0092

This publication supersedes T.O. 16G1-146-3 dated 20 April 1973.

DISTRIBUTION STATEMENT: Distribution authorized to the Department of Defense and U.S. DoD contractors only (Administrative or Operational Use) (31 December 2004). Other requests for this document or questions concerning technical content shall be referred to WR- ALC/LTET, 44 Green St., Warner Robins, GA 31093-2606.

WARNING: This document contains technical data whose export is restricted by the Arms Export Control Act (Title 22, U.S.C., Sec 2751 et.

seq.) or the Export Administration Act of 1979, as amended (Title 50, U.S.C. App. 2401 et. seq.). Violations of these export laws are subject to severe criminal penalties.

HANDLING AND DESTRUCTION NOTICE: Handle in compliance with the distribution statement and destroy by any method that will prevent disclosure of the contents or reconstruction of the document.

Published Under Authority of the Secretary of the Air Force

31 DECEMBER 2004

INSERT LATEST CHANGED PAGES. DESTROY SUPERSEDED PAGES.

LIST OF EFFECTIVE PAGES

NOTE: The portion of the text affected by the changes is indicated by a vertical line in the outer margins of the page. Changes to illustrations are indicated by miniature pointing hands.

Changes to wiring diagrams are indicated by shaded areas.

Dates of issue for original and changed pages are:

Original . . . . . . . . . . . . . . . . . . . . 0 . . . . . . . . 31 December 2004

TOTAL NUMBER OF PAGES IN THIS MANUAL IS 30, CONSISTING OF THE FOLLOWING:

Page *Change Page *Change Page *Change No. No. No. No. No. No.

Title A i ii Blank iii iv Blank v vi Blank 1-1 1-2 Blank 2-1 - 2-11 2-12 Blank 3-1 3-2 Blank 4-1 4-2 Blank 4-3 - 4-6

*Zero in this column indicates an original page

A USAF

TABLE OF CONTENTS

Chapter Page Chapter Page

LIST OF ILLUSTRATIONS........................................i 2.7 Repair or Replacement ...............................2-5

2.7.1 Repair..........................................................2-5

2.7.2 Heli-Coil Insert Replacement.....................2-5

LIST OF TABLES........................................................i 2.7.3 Repair of Painted Surfaces.........................2-5

2.7.4 Painting Procedures ....................................2-5

2.7.5 Touch-Up Painting Procedures ..................2-6

INTRODUCTION.......................................................iii 2.7.6 Repainting ...................................................2-7

2.7.7 Application of Epoxy Primer .....................2-7

2.7.8 Preparation Of Enamel ...............................2-7SAFETY SUMMARY.................................................v

2.7.9 Application of Enamel ...............................2-8

2.8 Lubrication..................................................2-8

2.9 Reassembly .................................................2-81 GENERAL INFORMATION...................................1-1

2.9.1 Shim Calculations.......................................2-8

2.10 Assemble Gearbox......................................2-91.1 General........................................................1-1

1.2 Leading Particulars .....................................1-1

3 TEST PROCEDURE ................................................3-1

2 OVERHAUL INSTRUCTIONS...............................2-1

3.1 Backlash Test..............................................3-1

3.2 Friction Torque Test...................................3-12.1 Special Tools ..............................................2-1

2.2 Disassembly ................................................2-1 4 DIFFERENCE DATA SHEETS ..............................4-12.3 Cleaning ......................................................2-3

2.4 Inspection....................................................2-3

4.1 Introduction.................................................4-12.5 Spline Inspection ........................................2-4

4.2 Index to Part Numbers ...............................4-12.6 Gear Inspection...........................................2-4

LIST OF ILLUSTRATIONS

Number Title Page Number Title Page

1-1 Nose Landing Gear Door 90 Degree 2-3 Typical Gear Nomenclature and Wear Gearbox Assembly ..................................... 1-1 Pattern......................................................... 2-6

2-1 Exploded View of Nose Landing Gear 2-4 Shim Determination T1 ................................ 2-10 Door 90 Degree Angle Gearbox As- 2-5 Shim Determination T2 ................................ 2-11 sembly......................................................... 2-2 3-1 Checking Backlash.......................................... 3-1

2-2 Service Tolerances .......................................... 2-3 4-1 Seal Assembly Part Number 177804-1.......... 4-3 4-2 Seal Assembly Part Number 177804-1.......... 4-5

LIST OF TABLES

Number Title Page Number Title Page

1-1 Leading Particulars............................................ 1-1 4-1 Special Tools ..................................................... 4-4 2-1 Special Tools ..................................................... 2-1 4-2 Special Tools ..................................................... 4-6 2-2 Non-Destructive Inspection .............................. 2-4 i/(ii blank)

INTRODUCTION

1. PURPOSE OF MANUAL. 4. LIST OF SYMBOLS AND ABBREVIATIONS.

This Technical Manual contains instructions for the over- The following symbols and abbreviations are used in this haul of the Nose Landing Gear Door 90 Degree Gearbox manual.

Assembly, part No. 177370, hereinafter referred to as the

° degreegearbox. This gearbox is manufactured by Curtiss Wright − minusFlight Systems, Inc., Fairfield, NJ, 07006.

+ plus Fig Figure2. SCOPE OF MANUAL.

in. inch

Chapter 1, Chapter 2, and Chapter 3 of this manual contain lb. pound overhaul and test instruction for Nose Landing Gear Door MSDS Material Safety Data Sheet 90 Degree Gearbox assembly, part No. 177370. Overhaul No. Number and test instructions for additional models will be provided psi pounds per square inch in Chapter 4 by the use of Difference Data Sheets. The T.O. Technical Order additional models included in Chapter 4 will be listed in Chapter 4.

3. LIST OF RELATED PUBLICATIONS.

The following list identifies technical manuals related to this manual.

List of Related Publications

Publication Number Publication Title

T.O. 0-1-44B-5 Maintenance Instruc-tions, Anti-Friction Bearings iii/(iv blank)

SAFETY SUMMARY

1. GENERAL SAFETY INSTRUCTIONS.

WARNING

This safety summary includes general safety precautions and instructions that must be understood and applied during operation and maintenance to ensure personnel safety and Highlights an essential operating or mainte-protection of equipment. Prior to performing any task, the nance procedure, practice, condition, statement, WARNINGs, CAUTIONs and NOTEs included in that task etc, which if not strictly observed, could result shall be reviewed and understood. in injury to, or death of, personnel or long term health hazards.

2. WARNINGS, CAUTIONS, AND NOTES.

CAUTIONWARNINGs and CAUTIONs are used in this manual to highlight operating or maintenance procedures, practices, conditions or statements which are considered essential to

Highlights an essential operating or mainte-protection of personnel (WARNING) or equipment (CAU-nance procedure, practice, condition, statement,TION). WARNINGs and CAUTIONs immediately precede etc, which if not strictly observed, could resultthe step or procedure to which they apply. WARNINGs and in damage to, or destruction of equipment orCAUTIONs consist of four parts: heading (WARNING, loss of mission effectiveness.CAUTION or Icon [see HAZARDOUS MATERIALS

WARNINGS]), a statement of the hazard, minimum pre- NOTEcautions, and possible result if disregarded. NOTEs are used in this manual to highlight operating or maintenance Highlights an essential operating or mainte-procedures, practices, conditions or statements which are nance procedure, condition, or statement.not essential to protection of personnel or equipment.

NOTEs may precede or follow the step or procedure, depending upon the information to be highlighted. The headings used and their definitions are as follows.

v/(vi blank)

CHAPTER 1

GENERAL INFORMATION

The gearbox shown in Figure 1-1 is a part of the aircraft1.1 GENERAL.

nose landing gear door actuation system. The gearbox provides a 90 degree change in direction of the torque

NOTE necessary to operate the nose landing gear doors.

Many repair parts for equipment covered in this 1.2 LEADING PARTICULARS.

publication are provided in the form of kits. See applicable Illustrated Parts Breakdown for The leading particulars for the gearbox are given in details. Activities shall replace all parts (regard- Table 1-1.

less of condition) which are removed in the process of disassembly with all like parts fur-nished in the kit. Therefore, instructions for Table 1-1. Leading Particulars cleaning, inspecting, and reworking used parts have been omitted. If any parts in the kit must be cleaned, inspected or tested prior to installa- Angle Between Input and 90 degrees tion, instructions for performing these require- Output Shafts ments are included in the manual. An installed

Height 7 inchespart which is not defective need not be Width 5 inchesremoved solely for the purpose of replacement by a corresponding kitted part. Residue from Length 6.250 inches kit and removed parts in this category shall be Weight 3.4’71 lbs (avg) administratively condemned.

Gear ratio 1:1

Figure 1-1. Nose Landing Gear Door 90 Degree Gearbox Assembly

1-1/(1-2 blank)

CHAPTER 2

OVERHAUL INSTRUCTIONS

f. During disassembly, discard seals, seal protectors,2.1 SPECIAL TOOLS.

packings and seal assemblies.

The special tools required to overhaul the gearbox are listed

g. Mount the gearbox in a padded vise.in Table 2-1.

h. Remove bolts (8), washers (9), screws (21), and

2.2 DISASSEMBLY. retainers (7, 20). Remove screw (1) and nut (2) from bevel gear (15).

a. The gearbox being repaired shall be surface cleaned and tested in accordance with Chapter 3 i. Compress the ends of seal retaining spring (3) and prior to disassembly. remove seal assembly (4, 5, and 6) with Removal

Tool, part No. ST5999.

b. The discrepancy should be located to the subas-sembly and the extent of repair determined. j. Compress the ends of seal retaining spring (16) and remove seal assembly (17, 18, and 19) with

c. Disassemble only to the extent necessary to replace Removal Tool, part No. ST5999.

or repair by parts replacement those subassemblies found defective.

CAUTION

d. The gearbox should again be tested to assure serviceability.

During the pressing operation, protect gears

e. Disassemble the gearbox in the order of ascending with soft stock such as aluminum.

callout number of Figure 2-1. Measure, record, and

k. Remove bearings (13) and (14) from gear (15),identify the thickness of all shims as disassembled.

using Plate, part No. ST5806, and an arbor press.If the same parts are used together in reassembly, the shim size shall remain the same.

Table 2-1. Special Tools

Part No. Nomenclature Procuring Service Stock No.

ST5806 Plate, Support (Part of Kit ST792)

ST5808 Adapter, Torque Wrench FSN 5120-121-3684LH

ST5902 Fixture, Gearbox

ST5903 Adapter, Gearbox FSN 4920-132-1596LH

ST5999 Removal Tool, Seal FSN 5120-520-3905LH

ST6278 Gage, Internal Spline (Part of Kit ST799)

ST6366-2 Setmaster, Internal (Part of Kit ST799)

ST792 Tool Kit, Installing and Removal, Bearing and Sea FSN 5180-117-6045LH

ST798 Fixture, Gearbox bevel gear shimming FSN 4920-132-3787LH

ST799 Gage Kit, Actuator drive components FSN 5280-420-7093LH

125105 Inspection Unit, Fluorescent Penetrant FSN 6635-334-7419

LFM1A Lamp Magnifier FSN 6650-967-8316

OP2-85 Degreaser

RCQ-1086 Inspection Unit, Magnetic FSN 6635-575-4642

2-1

Figure 2-1. Exploded View of Nose Landing Gear Door 90 Degree Angle Gearbox Assembly

2-2

Figure 2-2. Service Tolerances

Clean all metal parts using cleaning solvent, Federal Speci-fication MIL-PRF-680A. Blow dry with clean air. UseNOTE Degreaser, part No. OP2-85 to perform cleaning operation.

Presence of a new part in the applicable kit

2.4 INSPECTION.eliminates the necessity of cleaning, inspecting, or reworking the equivalent used part removed Perform the following inspections of paragraph 2.4 thrufrom the assembly being repaired. Residue paragraph 2.6. The tolerances listed in Figure 2-2 are to befrom kits and removed parts in this category used for establishing the serviceability of parts when wearshall be administratively condemned. The or improper fit is evident.instructions which follow cover removed parts not supplied in kits and kitted parts (if any) which require cleaning, inspection, or testing NOTE prior to installation.

Magnetic particle inspection or fluorescent pen-

l. Remove bearings (25 and 26) from gear (27), using etrant inspection must be used for parts sus-plate, part No. ST5806, and an arbor press. pected of being defective due to abuse or overload. After magnetic particle inspection, all

2.3 CLEANING. parts must be demagnetized and the magnetic

substance shall be completely removed.

WARNING a. Examine parts for condition, specifically those associated with malfunction. Perform a magnetic particle inspection or a fluorescent penetrant

Use of cleaning agents must be accomplished inspection in accordance with (ASTM E 1417) and with necessary precaution to avoid skin irrita- (ASTM E 1444), respectively, for all parts listed in tions or injury to eyes. Table 2-2. Use part No. RCQ-1086, FSN 6635-

575-4642, and part No. 125105, FSN 6635-334- 7419 respectively.

2-3

Table 2-2. Non-Destructive Inspection

Type of Part No. Name Inspection Procedure Acceptable Indications 177278 Gear * CB1500A #

177534 Bolt * CB500A #

177353 Housing **

117358 Retainer **

117359 Retainer **

A - Amperage preceded by the current value in amperes

CH - Circular Head

CB - Circular Bar

LC - Longitudinal Coil

LH - Longitudinal Head

X - Between Heads

* Magnetic Particle Method # All indications except cracks caused by fatigue or over stressing ** Fluorescent Penetrant Method

b. Inspect ball bearings in accordance with Reposition gage by moving gage dial in or out T.O. 0-1-44B-5, ‘‘Maintenance Instructions, Anti- of holder. Tighten set screw.

Friction Bearings.’’

(2) Tighten all threaded parts by hand except the Allen screw.2.5 SPLINE INSPECTION.

c. With the internal gage positioned on the proper NOTE setmaster set the dial indicator of the gage to read zero.

When measuring spline wear, special dial indi-cator gages and ball anvil sets are required. The d. Determine spline wear over entire length of available gages are designed for specific inter- splines. Refer to Figure 2-2 for wear tolerances.

nal and external spline inspection application The dial indicator reading is the actual wear on the and are parts of Kit, part No. ST799. splines. Replace part if worn beyond tolerances.

a. Prior to use of gage, set it to measure the proper 2.6 GEAR INSPECTION.

spline diameter, which is accomplished with the appropriate setmaster, specified in Figure 2-2. a. Inspect all gears using an illuminated magnifier

(part No. LFM1A).

b. Gage part No. ST6278 is used to measure internal spline wear on pitch diameters from 0.600-1.125 NOTEinch. Two ball sizes 0.07217 and 0.05774 inch are utilized with this gage. Applicable Setmasters, part

• Wear may be visually detected on someNo. ST6366 are available through the required gears by a wear step or a visible change inrange of pitch diameters. (Refer to Figure 2-2, item tooth profile. Visual comparison can be7 for specific tool sizes). Assemble the gages in the readily made between the loaded andfollowing manner:

unloaded sides of teeth, or between teeth of a used gear and a new gear. Normal tooth(1) When measuring the part No. 177278 gear pitch polishing, indicated by a shiny pattern,diameter of 0.6875 inch, use gage head with ball should not be considered as wear.size of 0.05774 inch. Assemble short extension of gage ball with head, tighten small lock ring • If a bevel gear is replaced for apparent wear, securely. If gage dial deflection adjustment is the mating gear must also be replaced.

required, loosen set screw with Allen wrench.

2-4

b. Replace gears exhibiting any of the following f. Inspect the insert to ensure that the tang broke off conditions: clean and the insert ends are firmly seated.

(1) Any displaced metal, horizontal and vertical 2.7.3 Repair of Painted Surfaces.

indentions, or pitting in the face or flank area.

See wear pattern A in Figure 2-3.

WARNING(2) Wear which tends to round the top edge of a tooth decreasing the top land thickness and the face area. See wear pattern B in Figure 2-3. Conduct all preparation and painting operations as directed throughout this chapter in a well-

(3) Any tooth edge breakage or chipping. ventilated area or in an approved spray booth equipped with adequate ventilation and

2.7 REPAIR OR REPLACEMENT. exhaust.

2.7.1 Repair. Replace all parts that do not meet inspec- Painting procedures cover repair of painted surfaces as tion requirements or that cannot be repaired by these outlined in paragraph 2.7.8 and paragraph 2.7.9.

instructions.

2.7.4 Painting Procedures. Prepare surfaces of various

a. Remove minor scratches, burrs, and corrosion from materials as follows:

steel parts by polishing lightly with crocus cloth, Federal Specification ANSI B74.18. After repair, WARNINGclean all parts thoroughly.

Acetone and methyl-ethyl-ketone are extremelyCAUTION flammable (flash points of 0 °F and 16 °F);

methyl-propyl-ketone is highly flammable

Do not use crocus cloth on aluminum parts. Its (flash point 45 °F). All three solvents are toxic.

abrasive is a ferric oxide which causes alumi- Use in a well-ventilated area. Keep away from num to corrode rapidly. open flame and other ignition sources. Avoid breathing vapors and spray mist. Avoid eye and

b. Remove minor defects from aluminum parts by skin contact. Safety glasses and protective polishing lightly with No. 400 or No. 320 alumi- gloves are required. Wash hands after use.

num oxide or silicon carbide abrasive cloth, Fed- Remove contaminated clothing and launder eral Specification ANSI B74.18. After repair, clean before use. Refer to MSDS for additional parts thoroughly. information.

2.7.2 Heli-Coil Insert Replacement. See Figure 2-1, NOTE

28.

• Repair refers to a condition in which thea. Remove the defective insert with Extracting Tool base metal is exposed through the paint.No. 1227-6, or equivalent.

• Lower vapor pressure solvents may require

b. Clean and dry the female thread from which the increased drying times.

defective insert was removed.

a. Aluminum Alloys.

c. Apply primer (Federal Specification TT-P-1757B) sparingly to the cleaned female thread. (1) Feather-edge the film adjacent to the damaged area using No. 400 or No. 320 silicon carbide

d. Before the primer dries, install new insert using abrasive cloth (Federal Specification ANSI installing tool No. 7552-4 (1/4-28 thd) or equiva- B74.18). Wipe surface clean with a cloth wetted lent. Top end of insert shall be 3/4 to 1-1/2 threads with methyl-ethyl-ketone (Federal Specification below the surface. ASTM D740) or a 50/50 blend of methy-ethyl-ketone (ASTM D740) and acetone (ASTMe. Remove the insert driving tang with Tang Breakoff D329) or methyl-propyl-ketone (MPK) (BACTool No. 1196-4 (1/4-28 thd) or equivalent.

5750) and wipe dry.

2-5

Figure 2-3. Typical Gear Nomenclature and Wear Pattern

(2) Apply Iridite No. 14-2 solution (MIL-C-5541E), solution to the affected area. When Iridite 8P is four ounces of Iridite per gallon of water at used as specified the requirements of AMS-QQ-room temperature with a brush or swab to the P-416A, Type II, Class 2 are met. If an equiva-exposed area. A contact time of 15 to 30 lent is selected, consideration must be given to seconds will usually produce a golden yellow assure that it also meets the requirements of color. Rinse thoroughly with water and dry. AMS-QQ-P-416A, Type II, Class 2.

b. Cadmium-Titanium Plated Steel or Cadmium (5) Keep the surface wet with the mixed solution Plated Steel. until the desired color is obtained. Rinse thor-oughly with water and dry.

(1) Feather-edge the film adjacent to the damaged area using No. 400 or No. 320 silicon carbide 2.7.5 Touch-Up Painting Procedures. Prepare sur-abrasive cloth (Federal Specification ANSI faces for minor repair as follows:

B74.18).

(2) Wipe clean with a cloth wetted with methyl- WARNING ethyl-ketone (Federal Specification ASTM D740) and wipe dry.

Acetone and methyl-ethyl-ketone are extremely

(3) With a brush or swab, clean the affected area flammable (flash points of 0 °F and 16 °F);

with an approved alkaline cleaner until it is methyl-propyl-ketone is highly flammable completely wetted and shows no water breaks. (flash point 45 °F). All three solvents are toxic.

Rinse thoroughly. Use in a well-ventilated area. Keep away from open flame and other ignition sources. Avoid

(4) Prepare a solution of one ounce of Iridite 8P, breathing vapors and spray mist. Avoid eye and manufactured by Allied Research Products, Inc., skin contact. Safety glasses and protective 4004 E. Monument Street, Baltimore, MD, gloves are required. Wash hands after use.

21205 (or equivalent), 0.406 fluid ounces (12 Remove contaminated clothing and launder milliliters) of concentrated nitric acid (Federal before use. Refer to MSDS for additional Specification A-A-59105B), and sufficient information.

water to make one gallon of solution. Apply the

2-6 shall be applied to the prepared surface within eight hours from the time of initial mixing.NOTE Primer not used within this period shall be discarded.• Lower vapor pressure solvents may require increased drying times.

a. Prepare the epoxy primer (MIL-PRF-23377H) in

• Repair refers to a condition in which one or accordance with the manufacturer’s recommenda-more of the paint films has been damaged tions under clean conditions and with clean without exposing the base metal. equipment.

a. Feather-edge the film adjacent to the damaged area b. Mix the components at room temperature. Remove using No. 400 or No. 320 silicon carbide abrasive skins if present.

cloth, Federal Specification ANSI B74.18, being

c. Thin the mixed primer to a viscosity of 17 to 19careful not to expose the base metal.

seconds in a No. 2 Zahn cup by the addition of

b. Wipe area with methyl-ethyl-ketone (ASTM D740) approximately three volumes of thinner to four or a 50/50 blend of methy-ethyl-ketone (ASTM volumes of the mixed primer. The thinner shall be D740) and acetone, (ASTM D329) or methyl- a 1:1 mixture by volume of methyl-isobutyl-propyl-ketone (MPK) (BAC 5750) and dry. ketone, Federal Specification ASTM D1153 and toluene, Federal Specification A-A-59107.

c. Apply one coat of epoxy primer (MIL-PRF-

23377H) per paragraph 2.7.8 and two coats of d. Thoroughly stir the mixed primer while thinning.

polyurethane enamel per paragraph 2.7.9. Strain the primer after thinning and allow to stand in a closed container for one hour prior to use.

2.7.6 Repainting. The affected area shall be repainted

e. The primer is to be applied in a single wet pass bywith the following: one coat of epoxy primer (MIL-PRF-spraying; when necessary, the fill-and-drain2337H) and two coats of polyurethane enamel manufac-method may be used for inaccessible surfaces. Thistured by De Soto Chemical Coatings, Inc., Garland, TX, method consists of wetting the inaccessible sur-(manufacturer’s designation 82 1-010/910-177, Gloss faces by pour-filling with primer and then drainingWhite), or U.S. Paint, Lacquer, and Chemical Co., St.

the primer. A prime coating is thus left on theLouis, MO, (manufacturer’s designation 91-W-1, Gloss surfaces.white), or Andrew Brown Co., Irving, TX, (manufacturer’s designation A-1250-66/7-1070-66, Gloss White).

f. The average dry film thickness of each coat of epoxy primer shall be 0.0004 to 0.0007 inch.2.7.7 Application of Epoxy Primer. Prior to applying epoxy primer, mix and thin the primer as follows:

g. A minimum air drying time of one hour and a maximum of eight hours shall elapse before apply-ing the polyurethane enamel. When these maxi-WARNING mum time limits have been exceeded, the epoxy primed surface shall be scuff-sanded using No. 400

• Primer-Epoxy Polyamide MIL-PRF- or No. 320 silicon carbide abrasive cloth, Federal 23377H is highly toxic to skin, eyes, and Specification ANSI B74.18, and reactivate with respiratory tract. Skin, eye, and respiratory methyl-ethyl-ketone Federal Specification ASTM protection is required. D740 and then cleaned and dried prior to applying enamel. No oven drying processes shall be used.• Methyl-Isobutyl-Ketone, Methyl-Ethyl- Ketone and toluene are flammable and h. Full closed containers of both components have a highly toxic. Use only in a well-ventilated storage life of one year from date of manufacture area. Avoid prolonged breathing of vapors. when stored at temperature of 70° to 90 °F.

Avoid eye and skin contact. Use personal protective equipment, goggles/face shield 2.7.8 Preparation Of Enamel. Prior to applying and gloves when handling. Keep away from enamel, prepare the enamel as follows:

open flames or other sources of ignition.

When not in use, close containers securely. NOTE

NOTE The mixing of paints supplied by different manufacturers is prohibited, to avoid any possi-

The surfaces to be painted shall be clean, dry bility of incompatibility.

and free from dust, dirt, oil, or other foreign matter. The epoxy primer (MIL-PRF-23377H)

2-7

a. The components to be mixed shall be at room product of Turco Products, Inc., Wilmington, CA, temperature (70 °F minimum) and the mixing shall or equivalent.

be done with clean equipment.

2.8 LUBRICATION.

b. The polyurethane enamel shall be vigorously shaken on a ‘‘Red Devil’’ shaker, or equivalent, During reassembly, pack bearings and lubricate all working before mixing with the isocyanate/thinner surfaces and seals with a mixture of five parts (Specifica- (supplied). tion MIL-PRF-23827A) grease blended with one part

(Specification MIL-PRF-7808L) oil.

c. The enamel shall be prepared by mixing the two components in a 1:1 volume ratio, stirring thor-

2.9 REASSEMBLY.oughly, straining, and allowed to stand for one hour before use. No thinning is required.

NOTE

2.7.9 Application of Enamel. Apply two coats of poly-

Just prior to installing, coat OD of all hearingsurethane enamel.

and seals with primer (Federal Specification

a. The polyurethane enamel shall be applied either by TT-P-1757B).

spray or brush to properly prepared surfaces within

To ensure proper tooth bearing and backlash, the beveleight hours from the time of initial mixing. Enamel gears must locate in the housing at the design mountingnot used within this period shall be discarded. After distances (MD). See Figure 2-4 and Figure 2-5. Shims (12)mixing, pot life is eight hours at 70° to 90 °F.

and (24), Figure 2-1 of the proper thickness, which must be

b. When using the spraying method, a high air atomi- calculated, are used to locate the gears.

zation pressure (40 to 60 psi) has been found to produce a coating with good leveling properties 2.9.1 Shim Calculations.

and without causing ‘‘orange peel.’’ Grounding the tables or racks holding the parts has been found

NOTEadvantageous, since it prevents a build-up of a static charge which could attract airborne dust

Shimming shall be done to properly locate theparticles.

bevel gears only. It shall not be done to obtain correct backlash. If parts originally removedc. The epoxy-primed surfaces to be enamelled shall are reassembled together, the shim sizesbe clean and dry. Any surfaces which require repair recorded at disassembly should provideshall be prepared in accordance with paragraph required dimensions and calculation procedure2.7.4 and paragraph 2.7.5 prior to applying enamel.

may be omitted.If more than eight hours time has elapsed since the application of the epoxy primer (MIL-PRF- Make all measurements to the nearest 0.0005 inch. Com-23377H) the primer coat shall be scuff-sanded and pare dimensions with stacked gage blocks, or equivalent.solvent activated with methyl-ethyl-ketone Federal After calculating, keep affected parts mated. All assemblySpecification ASTM D740 or both, then cleaned requirements to be accomplished per detailed instructionsand dried just prior to applying enamel.

of paragraph 2.10.

d. Drying time to be one hour before handling and dry

a. Calculate shim thickness to be used in retainerhard is not more than eight hours. Full cure will be

(Figure 2-1, 7). Refer to Figure 2-4 for use ofachieved in seven days. Oven dry process is to Fixture, part No. ST798.bake dry for 15 to 20 minutes in an oven at 200 °F.

(1) Install bearing (Figure 2-1, 14) in retainer (7)e. All marking applied over the polyurethane enamel and place in Fixture, part No. ST798; load theshall be made with a gloss black polyurethane bearing, by tightening the Thumbscrew, partstencil enamel.

No. ST5902-8, until the screw clicks. This pro-vides a 10-pound load. While in the loadedf. Removal of polyurethane enamel, when necessary, condition, measure dimension Al.can be made using stripper part No. T-5003, a

2-8

(2) Calculate the shim thickness, T1, using the as this may result in jammed bevel gears. This following formula: is apparent if a noticeable stiffness is present when shafts are manually rotated. Since only T 1 = B 1 - C 1 seal friction normally is present, free gearboxes rotate fairly easily. If jamming occurs, eitherWhere:

rotate shafts until free, or hold box shaft and, B1 = 2.3XX (Use actual dimension using a plastic mallet only, tap housing at marked on housing parting surface). various locations until gears are free.

C1 = A1 + MD + 0.004 inch

Reassemble the gearbox in the reverse order of disassem-bly, except as noted as follows:b. Peel shims to the calculated thickness within the limits of +0.000 to -0.002 inch. Smooth all burrs.

See Figure 2-4. NOTE

c. Calculate shim thickness to be used in retainer Lubricate all moving parts and pack bearings (20). See Figure 2-5 for use of Fixture, part No. with grease. (Refer to paragraph 2.8).

ST798.

a. Install bearings (25, 26) on bevel gear (27) using

(1) Install bearing (Figure 2-1, 26) in retainer (20) Plate, part No. ST5806, and an arbor press.

and place in Fixture, part No. ST798; load the bearing, by tightening the Thumbscrew, part b. Coat OD of bearings with primer (Federal Specifi- No. ST5902-8, until the screw clicks. This pro- cation TT-P-1757B) and insert bevel gear (27) into vides a 10-pound load. While on the loaded housing (29) and install shim (24). Refer to condition, measure dimension A2. Figure 2-5 for correct thickness of shim.

(2) Calculate the shim thickness, T2, using the c. Place packings (22, 23) onto retainer (20), install following formula: retainer (20) using screw (21) and secure to the housing (29). Torque per reference 1, Figure 2-2.

T 2 = B 2 - C 2

d. Install seal assembly (17, 18, 19) and spring (16)Where:

using Removal Tool, part No. ST5999.

B2 = 2.3XX (Use actual dimension marked on housing parting surface). e. Install bearings (13, 14) on bevel gear (15) using

Plate, part No. ST5806, and an arbor press.C2 = A2 + MD + 0.004 inch

f. Coat OD of bearings with primer (Federal Specifi- NOTE cation TT-P-1757B) and insert bevel gear (15) into housing (29) and install shim (12). Refer to Use the same MD for calculating T2 as was Figure 2-4 for correct thickness of shim.

used for calculating T1.

g. Place packings (10, 11) onto retainer (7), install

d. Peel shims to the calculated thicknesses within the retainer (7) using bolt (8) and washer (9) and limits of +0.000 to -0.002 inch. Smooth all burrs. secure to housing (29). Torque per reference 2, Figure 2-2.

2.10 ASSEMBLE GEARBOX.

h. Install seal assembly (4, 5, 6) and spring (3) using

Removal Tool, part No. ST5999.

CAUTION

i. Install screw (1) and nut (2) into bevel gear (15), after completion of Chapter 3 tests.

Avoid undue pressure or shock loads on ends of shafts when gears and bearings are installed

2-9

Figure 2-4. Shim Determination T1

2-10

Figure 2-5. Shim Determination T2

2-11/(2-12 blank)

CHAPTER 3

TEST PROCEDURE

Figure 3-1. Checking Backlash and the shims checked for correct thickness. If3.1 BACKLASH TEST.

procedures and shims are correct, equal thick-ness of shims must be added to both gears toTest the assembled gearbox for backlash. Conduct tests at obtain an acceptable backlash. Do not addroom temperature. First, shock or load the gears in the shims to one gear only.direction which increases the gear mounting distance to seat the bearings and flatten the shims.

f. Read indicator. The backlash is acceptable if indi-cator reads between 0.017 and 0.046 inch. If lessa. Install the assembled gearbox on Adapter, part No.

than 0.017 or more than 0.046 inch, disassembleST5903. Refer to Figure 3-1.

and recheck all of the shimming measurements to determine the cause of the error.b. Lock the output shaft with the ST5903-3 support clamp. Attach the adapter weight arm in a horizon-tal position to the input shaft using the supplied 3.2 FRICTION TORQUE TEST.

hardware.

Test the assembled gearbox for friction torque. Conduct

c. Place the ST5903-23 weight over the locating pin test at room temperature.

on the end of the weight arm opposite the dial indicator. a. With both gears free, rotate one gear five turns clockwise and five turns counterclockwise using

d. Zero the indicator. Adapter, part No. ST5808, and a 0 to 25 inch-pound torque wrench.

e. Move the weight to the indicator end of the weight arm, placing it over the locating pin. b. The force required to turn the gears shall not exceed 0.10 inch-pounds torque at any location.

NOTE

c. Install screw (1) and nut (2) into bevel gear (15).

If backlash is not acceptable, the shim measur-ing procedures must be repeated for accuracy

3-1/(3-2 blank)

CHAPTER 4

DIFFERENCE DATA SHEETS

4.1 INTRODUCTION.

4.2 INDEX TO PART NUMBERS.

Overhaul and test procedures for the models included in The following index lists applicable part numbers andthis chapter are the same as the procedures for Gearbox corresponding page numbers of respective difference dataAssembly Part Number 177370, except for the specific sheets.differences noted by the applicable Difference Data Sheets.

Chapter 1 thru Chapter 3 contain complete overhaul and test information for the 177370 Gearbox Assembly.

Part No. Nomenclature Page 177370-1 Nose Landing Gear Door 90 Degree Gearbox Assembly 4-3

177370-2 Nose Landing Gear Door 90 DegreeGearbox Assembly 4-5

4-1/(4-2 blank)

DIFFERENCE DATA SHEET

NOSE LANDING GEAR DOOR 90 DEGREE GEARBOX ASSEMBLY PART NO. 177370-1

THE INSTRUCTIONS CONTAINED IN THE PRECEDING CHAPTERS OF THIS TECHNICAL MANUAL ARE APPLICABLE TO THIS MODEL EXCEPT FOR THE DIFFERENCES CITED IN THIS DIFFERENCE DATA

SHEET.

1. CHARACTERISTIC DIFFERENCES.

6. TESTING DURING OVERHAUL.

Nose Landing Gear Door 90 Degree Gearbox Assembly, Same as for Part Number 177370.Part Number 177370-1 is physically and functionally iden-tical to Gearbox Part Number 177370, except that configur-

7. REPAIR OR REPLACEMENT.ation of seal assemblies (Figure 2-1, 4, 5, 6) and (Figure 2-

1, 17, 18, 19) are different by containing seal (Figure 4-1, Same as for Part Number 177370.1), Part Number 178746-1 in place of seal Part Number

177298 and seal (Figure 4-1, 2), Part Number 178747-1 in place of protector, Part Number 177286. 8. LUBRICATION.

Same as for Part Number 177370.2. SPECIAL TOOLS.

Same as for Part Number 177370 with addition of tools 9. REASSEMBLY.

listed in Table 4-1.

Same as for Part Number 177370 except paragraph 2.10 step d and step h do not apply. Seal assembly Part Number3. DISASSEMBLY.

177804-1 is assembled and installed to gearbox Part Num-ber 177370-1 as follows:Same as for Part Number 177370 except seal assembly Part

Number 177804-1 removed in accordance with paragraph

a. Pack cavity in seal (Figure 4-1, 1) with grease,2.2, step i and paragraph 2.2, step k are disassembled as

(refer to paragraph 2.8) and coat OD of sealsfollows: Remove seals (Figure 4-1, 1, 2) from retainer (Figure 4-1, 1, 2) with sealing compound (Specifi-(Figure 4-1, 3) using Plate, Part Number ST5803, cation SAE-AMS-8802A) and immediately installInserter/Remover, Part Number ST5804, and an arbor seals into retainer (Figure 4-1, 3) with sealing lipspress.

facing outer end of retainer. Use Plate, Part Num-ber ST5804 and Inserter/Remover, Part Number4. CLEANING.

ST5804 with an arbor press to install seals. Wipe excess sealant from retainer.Same as for Part Number 177370.

b. Fill cavity between seals (Figure 4-1, 1 and 2) and

5. INSPECTION. between lips of seal (Figure 4-1, 1) with grease.

(Refer to paragraph 2.8). Install seal assemblies Same as for Part Number 177370. (Figure 4-1) in retainers (Figure 2-1, 7, 20) using packing (Figure 2-1, 10, 22) and springs (Figure 2- 1, 3, 16).

10. TEST PROCEDURE.

Same as for Part Number 177370.

Figure 4-1. Seal Assembly Part Number 177804-1

4-3

Table 4-1. Special Tools

Part No. Nomenclature Procuring Service Stock No.

ST5803 Plate, Support (Part of Kit ST792)

ST5804 Inserter/Remover, Seal and Protector (Part of Kit

ST792)

4-4

NOSE LANDING GEAR DOOR 90 DEGREE GEARBOX ASSEMBLY PART NO. 177370-2

THE INSTRUCTIONS CONTAINED IN THE PRECEDING CHAPTERS OF THIS TECHNICAL MANUAL ARE APPLICABLE TO THIS MODEL EXCEPT FOR THE DIFFERENCES CITED IN THIS DIFFERENCE DATA

SHEET.

1. CHARACTERISTIC DIFFERENCES.

b. Gear/plug assembly, Part Number 177278-10 (Fig-ure 2-1, 15, 27) is not disassembled.Nose Landing Gear Door 90 Degree Gearbox Assembly, Part Number 177370-2 is physically and functionally iden-

4. CLEANING.tical to Gearbox Part Number 177370 except that configur-ation of seal assemblies (Figure 2-1, 4, 5, 6) and (Figure 2-

Same as for Part Number 177370.1, 17, 18, 19) are different by containing seal (Figure 4-2, 1), Part Number 178176-1 in place of seal Part Number

5. INSPECTION.177298 and seal (Figure 4-2, 2), Part Number 178747-1 in place of protector, Part Number 177296. Gear/plug assem-

Same as for Part Number 177370.bly Part Number 177278-10 (Figure 2-1, 15, 27) is used in lieu of bevel gear Part Number 177278. Identification plate

6. TESTING DURING OVERHAUL.Part Number 178117-96 (Figure 2-1, 30) is used in lieu of Part Number 178117-31.

Same as for Part Number 177370.

2. SPECIAL TOOLS.

7. REPAIR OR REPLACEMENT.

Same as for Part Number 177370 with addition of tools Same as for Part Number 177370.listed in Table 4-2.

8. LUBRICATION.3. DISASSEMBLY.

Same as for Part Number 177370.Same as for Part Number 177370 except or the following procedures:

9. REASSEMBLY.

a. Seal assembly Part Number 177804-1 is removed in accordance with paragraph 2.2, step i and para- Same as for Part Number 177370 except paragraph 2.10 graph 2.2, step k and is disassembled as follows: step d and step h do not apply. Seal assembly Part Number Remove seals (Figure 4-2, 1, 2) from retainer 177804-1 is assembled and installed to gearbox Part Num- (Figure 4-2, 3) using Plate, Part Number ST5803, ber 177370-2 as follows:

Inserter/Remover, Part Number ST5804, and an

a. Pack cavity in seal (Figure 4-2, 1) with greasearbor press.

(refer to paragraph 2.8) and coat the OD of seals (Figure 4-2, 1, 2) with sealing compound (Specifi-cation SAE-AMS-8802A) and immediately install seals into retainer (Figure 4-2, 3) with sealing lips facing outer end of retainer. Use Plate, Part Num-ber ST5803 and Inserter/Remover, Part Number ST5804 with an arbor press to install seals. Wipe excess sealant from retainer.

b. Fill cavity between seals (Figure 4-2, 1 and 2) and between lips of seal (Figure 4-2, 1) with grease.

(Refer to paragraph 2.8) Install seal assemblies (Figure 4-2) in retainers (Figure 2-1, 7, 20) using packings (Figure 2-1, 10, 22) and springs (Figure 2-1, 3, 16).Figure 4-2. Seal Assembly Part Number 177804-1

4-5

10. TEST PROCEDURE.

Same as for Part Number 177370.

Table 4-2. Special Tools

Part No. Nomenclature Procuring Service Stock No.

ST5803 Plate, Support (Part of Kit ST792)

ST5804 Inserter Remover, Seal and Protector (Part of Kit ST792)

4-6

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