Preliminary Requirements

Procedure

1. SUBTASK 72-60-21-320-079 Machine the Oil Tank Bore in the Gearbox Casing

   1. Refer to Figure and Figure.

   2. Machine the oil tank bore.

      1. The diameter of the bore must be between 7.2425 in. and 7.2441 in. (183.960 mm and 184.000 mm) after the removal of the damage.

      2. The true position of the bore must be within 0.0118 in. (0.300 mm) FIR in relation to W system and within 0.010 in. (0.250 mm) FIR in relation to Diameter 8.0315 in. (204.000 mm).

      3. Bore surface rough must be 63 micro inch (1.6 micron).

2. SUBTASK 72-60-21-220-116 Examine the Gearbox Casing

   1. Use a magnifying glass to inspect the Casing for cracks in the area of the bore.

3. SUBTASK 72-60-21-330-074 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 72-60-21-320-081 Optional produce a Bushing

   1. Refer to Figure.

   2. Produce a bushing.

      1. Outside diameter must be between 7.2594 in. - 7.2614 in (184.390 mm - 184.440 mm).

      2. Deleted.

5. SUBTASK 72-60-21-230-001 Do a Fluorescent Penetrant Inspection for Cracks

   1. Refer to SPM TASK 70-23-03-230-501.

   2. Cracks, markings appearing like cracks or through porosity are not allowed.

6. SUBTASK 72-60-21-310-001 Apply the Chromate Conversion Coating

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

7. SUBTASK 72-60-21-220-117 Do a Dimensional Inspection of the Outside Diameter

   1. Dimension to be checked as average of 6 equally spaced readings on 360 deg.

   2. 0.011 in (0.3 mm) out of roundness allowed on unconstrained part.

8. SUBTASK 72-60-21-350-090 Install the Bushing

   1. Refer to Figure and Figure.

   2. 

      CAUTION

      MAKE SURE THAT THE LEAD IN CHAMFER OF THE BUSHING POINTS AWAY FROM THE DRIFT.

      Install the bushing on the IAE 3F10349 Drift, bushing (dia 178) 1 off.

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

      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).

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

            NOTE

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

   4. Remove the casing from the oven and/or the assembled drift and busing from the freezer.

      1. Use protective gloves.

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

      Install the bushing into machined bore.

      1. Use IAE 3F10349 Drift, bushing (dia 178) 1 off and an arbor press.

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

   6. Let the parts get the ambient temperature.

   7. Remove the drift.

9. SUBTASK 72-60-21-320-080 Machine the Inner Diameter of the Bushing

   1. Refer to Figure and Figure.

   2. Machine the inner diameter of the bushing.

      1. The dimension must be between 7.0866 in. and 7.0891 in. (180.000 mm and 180.063 mm).

         1. Chamfer where necessary.

         2. The true position of the diameter must be within 0.0118 in. (0.300 mm) FIR in relation to W system and within 0.010 in. (0.250 mm) in relation to diameter 8.0315 in (204.000 mm).

         3. Bore surface rough must be 63 micro inch (1.6 micron).

10. SUBTASK 72-60-21-330-075 Apply the Chromate Conversion Coating

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

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

11. SUBTASK 72-60-21-350-091 Identify the Repair

    1. Refer to Figure and Figure.

    2. Make a mark VRS5258 adjacent to the part number.

       1. Refer to the SPM TASK 70-09-00-400-501, SUBTASK 70-09-00-400-001.

Figure: Repair All Details And Dimensions

Repair All Details And Dimensions



Figure: Repair All Details And Dimensions

Repair All Details And Dimensions



Figure: Dimensions Of The Bush

Dimensions Of The Bush