Preliminary Requirements

Procedure

1. SUBTASK 72-60-21-320-114 Machine the Oil Pressure Pump Bore in the Gearbox Casing

   1. Refer to Figure.

   2. Machine the oil pressure bore pump.

      1. The diameter of the bore must be between 5.1953 in. and 5.1968 in. (131.960 mm and 132.000 mm) after the removal of the damage.

      2. The position of the bore must be within 0.0031 in. (0.080 mm) FIR in relation to diameter A index 15 and diameter B index 22 (if diameter A or B are damaged refer to zone C index 18 or zone D index 19).

      3. The perpendicularity of the bore must be within 0.0031 in. (0.080 mm) FIR in relation to surface Z index 23.

      4. Bore surface rough must be 63 microin. (1.6 micron).

2. SUBTASK 72-60-21-220-158 Examine the Gearbox Casing

   1. Inspect the casing for cracks in locality of the oil pressure pump bore.

      1. Use a magnifying glass.

3. SUBTASK 72-60-21-330-101 Apply the Chromate Conversion Coating

   1. Apply the chromate conversion coating to the machined surfaces.

      1. Refer to the SPM TASK 70-38-02-300-503.

4. SUBTASK 72-60-21-350-127 Install the Bushing

   1. Refer to Figure.

   2. Install the bushing to drift.

   3. 
      WARNING
      DO NOT TOUCH THE HOT PARTS WITHOUT PROTECTIVE GLOVES.
      
      WARNING
      HOT PARTS CAN CAUSE REDDENING AND BLISTERING OF THE SKIN IF THE HANDS ARE NOT PROTECTED.
      
      WARNING
      IMMERSE THE CONTACTED AREA IN COLD WATER FOR 10 MINUTES IF THE SKIN IS BURNED. IMMEDIATELY GET THE MEDICAL ATTENTION IF PAIN OR BLISTERING PERSISTS.

      Use an oven and/or a freezer to increase the temperature of the casing and/or decrease the temperature of the assembled drift and bushing.

      1. Do not increase the temperature of the casing above 284 deg F (140 deg C).

      2. Do not decrease the temperature of the assembled drift and bushing below minus 58 deg F (minus 50 deg C).

   4. NOTE

      The difference in temperature between the parts must be 216 deg F (120 deg C).

      Use protective gloves to remove the casing from the oven and/or the assembled drift and bushing from the freezer.

   5. 
      CAUTION
      INSTALL BUSHING IN MACHINED BORE IMMEDIATELY AFTER REMOVAL FROM FREEZER, OTHERWISE BUSHING CANNOT BE CORRECTLY INSTALLED.

      Use drift and an arbor press to install the bushing into machined bore.

      1. Give sufficient back-up support at bushing bore area to prevent casing distortion when you install the bushing.

   6. Let the parts get to the room temperature.

   7. Remove the drift.

5. SUBTASK 72-60-21-320-115 Machine the Inner Diameter of the Bushing

   1. Refer to Figure.

   2. Machine the inner diameter of the bushing.

      1. The last dimension of the inner diameter must be between 5.0394 in. and 5.0409 in. (128.000 mm and 128.040 mm) after the removal of the damage.

      2. The position of the bore must be within 0.0016 in. (0.040 mm) FIR in relation to diameter A index 15 and diameter B index 22 (if diameter A or B are damaged refer to zone C index 18 or zone D index 19).

      3. The perpendicularity of the bore must be within 0.0016 in. (0.040 mm) FIR in relation to surface Z index 23.

      4. Bore surface rough must be 63 micro in. (1.6 micron).

      5. Chamfer where necessary.

6. SUBTASK 72-60-21-330-102 Apply the Chromate Conversion Coating

   1. Apply the chromate conversion coating to the machined surface of the bushing.

      1. Refer to the SPM TASK 70-38-02-300-503.

7. SUBTASK 72-60-21-350-128 Record the Repair

   1. Vibro engrave 'VRS5264' adjacent to the part number.

      1. Remove the metal lifted by marking.

Figure: Repair details and dimensions

Repair details and dimensions



Figure: Repair details and dimensions

Repair details and dimensions