Preliminary Requirements

Procedure

1. SUBTASK 72-60-41-350-091 Remove the Bush from the Gearbox Casing Bore (If Necessary)

   1. If VRS5703 or VRS5690 is marked near the part number mark, remove the bush from the Gearbox Casing Bore.

      1. Remove by machining the damaged bush from the gearbox casing bore.

2. SUBTASK 72-60-41-320-080 Machine the Gearbox Casing Bore

   1. Refer to Figure and Figure.

   2. Machine the two diameters of the bore.

      1. Machine Diameter U first.

      2. Diameter U must be between 3.658 in. to 3.665 in. (92.913 mm to 93.091 mm).

         1. If there is damage or unwanted runout, Diameter U can be increased to a maximum of 3.714 in. (94.34 mm). Keep material removal to a minimum.

      3. Axially machine Diameter U to 0.650 in. to 0.669 in. (16.510 mm to 16.993 mm).

      4. Diameter V must be between 3.815 in. to 3.822 in. (96.901 mm to 97.079 mm).

         1. If there is damage or unwanted runout, Diameter V can be increased to a maximum of 3.827 in. (97.21 mm). Keep material removal to a minimum.

      5. Axially machine Diameter V to 0.153 in. to 0.161 in. (3.886 mm to 4.089 mm).

         1. If there is damage, the axial length of Diameter V (Distance D) can be increased to a maximum of 0.234 in. (5.94 mm).

      6. Make sure you comply with tolerances.

      7. Record the actual dimensions of Diameter U, Diameter V, and Distance D.

      8. Use a boring machine.

3. SUBTASK 72-60-41-220-105 Examine the Gearbox Casing Bore

   1. Clean the part.

      1. Refer to TASK 72-60-00-100-000.

   2. Inspect the casing for cracks in the area of the bore.

      1. Refer to SPM TASK 70-23-01-230-501.

      2. Cracks are not allowed.

4. SUBTASK 72-60-41-330-081 Apply the Chromate Conversion Coating on Diameter V, Diameter U and Surface S

   1. Refer to Figure.

   2. Apply the chromate conversion coating to the Diameter V, Diameter U and Surface S.

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

5. SUBTASK 72-60-41-330-082 Produce a Bush

   1. Refer to Figure, Figure and Figure.

   2. Produce a bush.

      1. Use only steel alloy A286. Do not use other materials.

      2. The outside diameters must be equal to U plus 0.0032 in. to 0.0039 in. (0.081 mm to 0.099 mm) and to V minus 0.0040 in. to 0.0078 in. (0.102 mm to 0.198 mm).

      3. Make sure you comply with tolerances.

      4. Use a grinding machine or a lathe.

6. SUBTASK 72-60-41-350-092 Install the Bush

   1. Refer to Figure.

   2. 
      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 MEDICAL ATTENTION IF PAIN OR BLISTERING PERSISTS.

      Increase the temperature of the housing.

      1. Use an oven. Do not increase the temperature of the casing above 220° F (104° C).

         NOTE

         The difference in temperature between the parts must be 149° F (65° C).

   3. Apply glue in the bush grooves and on Diameter E.

      1. Use CoMat 08-180 RETAINING COMPOUND pressfit.

   4. 
      CAUTION
      INSTALL BUSH INTO THE MACHINED BORE OF THE CASING IMMEDIATELY AFTER THE CASING REMOVAL FROM THE OVEN.

      Remove the casing from the oven.

      1. Use protective gloves.

   5. Install the bush into the casing.

      1. Install the bush into the machined bore of the casing. Use an arbor press. Make sure that the casing is correctly installed on a support to prevent casing distortion when you install the bush.

   6. Let the parts get to room temperature.

      1. Let the parts get to room temperature at least for 48 hours to make sure sufficient cure time is given for glue.

7. SUBTASK 72-60-41-320-081 Machine the Bush

   1. Refer to Figure and Figure.

   2. Machine the top land and the inner diameter of the bush.

      1. Flush the top land of the bush to 0.005 in. (0.127 mm) below the surface of the angle gearbox casing.

      2. Use a grinding machine or a lathe.

      3. The final dimension of the inner diameter of the bush must be between 3.5040 in. to 3.5053 in. (89.002 mm to 89.035 mm). Make sure you comply with tolerances.

      4. Surface finish is 63 microinches (1.600 micrometers).

      5. Use a boring machine.

   3. Machine the chamfer of the bush.

      1. Surface finish is 63 microinches (1.600 micrometers).

      2. Use a grinding machine or a lathe.

8. SUBTASK 72-60-41-330-083 Apply the Chromate Conversion Coating

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

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

9. SUBTASK 72-60-41-340-002 Apply the Dry Film Lubricant

   1. Apply the dry film lubricant to the inner diameter.

      1. Use CoMat 10-140 DRY FILM LUBRICANT, MOLYBDENUM DISULFIDE according to SPM TASK 70-38-03-380-501.

10. SUBTASK 72-60-41-350-093 Identify the Repair

    1. Make a mark VRS5703 (if not already marked) adjacent to the part number.

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

       2. Used method 3 (Vibration peen).

    2. Apply the chromate conversion coating to areas affected by marking.

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

Figure: Repair Details Pre SBE 72-0492 and Post SBE 72-0492

Repair Details Pre SBE 72-0492 and Post SBE 72-0492



Figure: Machine the Gearbox Casing Bore

Machine the Gearbox Casing Bore



Figure: Bush

Bush



Figure: Bush

Bush



Figure: Detail H

Detail H



Figure: Install the Bushing

Install the Bushing



Figure: Machine the Bushing

Machine the Bushing



Figure: Machine the Bushing Chamfer

Machine the Bushing Chamfer