Preliminary Requirements

Procedure

1. SUBTASK 72-50-53-350-106 Remove the Inserts from the Turbine Exhaust Case

   1. Refer to Figure.

   2. Remove loose or damaged inserts from the turbine exhaust case.

      1. Refer to SPM TASK 70-35-27-300-501. Use Removal tool.

2. SUBTASK 72-50-53-220-194 Examine the Threads

   1. Examine the threads after you remove the insert.

      1. Use Thread plug gage for single helical coil or Thread plug gage for double helical coil.

      2. If the threads are damaged, do a single helical coil insert repair by Step, Step, Step and Step.

      3. If the hole threads are not damaged, replace the single helical coil by Step and Step.

      4. If the hole threads are damaged more than the limits of a single helical coil insert, do a double helical coil insert repair by Step, Step, Step, Step and Step.

   2. Do a dimensional inspection of the repair area at the Turbine Exhaust Case to make sure that there is sufficient minimum wall thickness for machining.

      1. Refer to Figure, Figure and Figure.

         NOTE

         If the hole is already tapped for a double helical wire thread insert, it is permitted to install a double helical coil thread insert by Step, Step and Step, subject to part meeting minimum wall thickness requirement.

3. SUBTASK 72-50-53-320-099 Machine the Damaged Threads

   1. Refer to Figure, Figure and Figure.

   2. Machine the damaged threads to the required thread minor diameter. See Figure, Figure and Figure.

   3. 

      CAUTION

      DO NOT DRILL OR TAP INTO THE CASE WALL WHEN YOU DO THE HOLE REPAIR.

      THE WALL THICKNESS OF THE BOSSES CANNOT BE DECREASED BELOW THE LIMITS SHOWN IN Figure, Figure AND Figure FROM THE MINOR DIAMETER OF THE THREADS.

      Machine the lead-in chamfer. See Figure.

   4. Tap the hole and remove the chips.

      1. Use Plug tap for single helical coil insert or Plug Tap for double helical coil insert.

4. SUBTASK 72-50-53-220-195 Examine the Threads

   1. Examine the threads after you have tapped them.

      1. Use Thread plug gage or Thread plug gage.

5. SUBTASK 72-50-53-350-107 Install the New Single Helical Coil Inserts

   1. Refer to Figure.

   2. Put the PN MS21209F4-15 insert onto the tip of the Installation tool.

   3. Put the insert into the threaded hole.

   4. Turn the handle clockwise so the top of the insert is one to one and a half pitch below the face of the boss.

   5. Break the tang of the insert at the notch using the Tang removal tool.

      1. Use Tang removal tool. Refer to SPM TASK 70-35-27-300-501.

6. SUBTASK 72-50-53-420-001 Install the Outer Double Helical Coil Inserts

   1. Refer to Figure, Figure and Figure.

   2. Put the PN 2391-4CN375 outer insert onto the tip of the Thread insert installation tool.

   3. Put the insert into the threaded hole.

   4. Turn the handle clockwise so the top of the insert is one to one and a half pitch below the face of the boss.

   5. Break off and remove tang using the Tang removal tool.

      1. Refer to SPM TASK 70-35-27-300-501.

7. SUBTASK 72-50-53-420-002 Install the Inner Double Helical Coil Inserts

   1. Refer to Figure, Figure and Figure.

   2. Put the PN 4691-4CN339 inner insert onto the tip of the insertion tool Installation tool.

   3. Put the insert into the threaded hole.

   4. Align the ends of the inner insert and the outer insert.

   5. Break off and remove tang using the Tang removal tool.

      1. Refer to SPM TASK 70-35-27-300-501.

8. SUBTASK 72-50-53-220-196 Examine the Repair

   1. Examine the new inserts.

      1. Refer to TASK 72-50-53-200-000 (INSPECTION-000).

Figure: Turbine Exhaust Case Assembly - No. 5 Bearing Housing Single And Double Helical Coil Inserts Repair

(1) Repair Areas On The No. 5 Bearing Compartment Cover Mating Flange Bolt Holes At 13 Locations Equally Spaced Over Arc P.



Legend

1

(1) Repair Areas On The No. 5 Bearing Compartment Cover Mating Flange Bolt Holes At 13 Locations Equally Spaced Over Arc P. (2) Top Face Of First Coil 1.0 To 1.5 Pitch Below This Surface. 13 Locations. (3) 0.071 in. (1.804 mm) Minimum To Thread Minor Diameter. (4) 341 Degrees 25 Minutes 12 Seconds (5) 57 Degrees 34 Minutes 6 Seconds (6) 7.510 in. (190.754 mm) Diameter. (7) 5.5210 in. - 5.5227 in. (140.234 mm - 140.276 mm) Diameter, Interrupted Surface, Reference. (8) 6.943 in. - 6.947 in. (176.352 mm - 176.454 mm) Diameter, Over Index [9] Distance, Reference. (9) 0.425 in. (10.795 mm) Minimum, Reference. NOTE: Break Edges 0.003 in. - 0.015 in. (0.0762 mm - 0.381 mm).

Close

Figure: Turbine Exhaust Case Assembly - No. 5 Bearing Housing Single And Double Helical Coil Inserts Repair

(1) Repair Areas On The No. 5 Bearing Retaining Plate Mating Flange Bolt Holes On The Turbine Exhaust Case Assembly At Six Locations. FIve Locations On The Basis Of Six Equally Spaced Locations And One Location Offset At R.



Legend

1

(1) Repair Areas On The No. 5 Bearing Retaining Plate Mating Flange Bolt Holes On The Turbine Exhaust Case Assembly At Six Locations. FIve Locations On The Basis Of Six Equally Spaced Locations And One Location Offset At R. (2) Top Face Of First Coil 1.0 To 1.5 Pitch Below This Surface. Six Locations. (3) For PN 2A1209-01, 0.071 in. (1.804 mm) Minimum To Thread Minor Diameter For All Other PNs, 0.059 in. (1.499 mm) Minimum To Thread Minor Diameter (4) 16 Degrees 16 Minutes (5) 38 Degrees 44 Minutes (6) 6.360 in. (161.544 mm) Diameter (7) 0.257 - 0.259 in. (6.528 mm - 6.578 mm) Diameter, Reference Note: Break Edges 0.003 in. - 0.015 in. (0.077 mm - 0.381 mm).

Close

Figure: Turbine Exhaust Case Assembly - No. 5 Bearing Housing Double Helical Coil Inserts Repair

Turbine Exhaust Case Assembly - No. 5 Bearing Housing Double Helical Coil Inserts Repair