Replacement of Defective Studs [CFMB]

TASK 72-56-00-300-003-A
Replacement of Defective Studs

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	Torque wrench: range to between 110 and 100 lbf.in (1.24 and 1.13 m.daN )
No specific	Torque wrench: range to between 270.0 and 244.0 lbf.in (3.05 and 2.76 m.daN )
No specific	Torque wrench: range to between 558 and 505 lbf.in (6.31 and 5.71 m.daN )

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.CP2101)	graphite grease

C. Referenced Information

REFERENCE	DESIGNATION
TASK 78-11-11-000-041-A	Removal of the Core Nozzle Assembly
TASK 78-11-11-400-041-A	Installation of the Core Nozzle Assembly
TASK 78-11-12-000-041-A	Removal of the Centerbody
TASK 78-11-12-400-041-A	Installation of the Centerbody
Replacement of the Defective Studs on the Turbine Frame
Machining of the Pin Hole
Locally Manufactured Pin
Locally Manufactured Tool

3. Job Set-up
Subtask 72-56-00-010-065-A ** ON A/C NOT FOR ALL

A. Get Access
(1) Remove the core nozzle (Ref. AMM TASK 78-11-11-000-041).
(2) Remove the centerbody (Ref. AMM TASK 78-11-12-000-041).

4. Procedure
Subtask 72-56-00-869-054-A ** ON A/C NOT FOR ALL

A. Preparation for Replacement
(1) Clear away the stud to repair by removing the attachment bolts on the rear flange of the two adjacent thermal insulation blankets and lifting them.

After SB 72-247

(2) Clear away the stud to repair by removing the attachment bolts and washers on the rear flange of the two adjacent thermal insulation blankets and lifting them.

END of SB 72-247

Subtask 72-56-00-350-052-A ** ON A/C NOT FOR ALL

B. Replacement of the Defective Studs

WARNING: DO NOT BREATHE THE PARTICLES FROM GRINDING OR DRILLING, OR LET THE PARTICLES TOUCH YOU. THE PARTICLES CAN CAUSE DAMAGE, INJURY OR IRRITATION TO YOU. USE PERSONAL PROTECTION EQUIPMENT. USE LOCAL MECHANICAL EXHAUST VENTILATION OR AN APPROVED RESPIRATOR.

WARNING: WHEN YOU USE COMPRESSED AIR:

USE THE CORRECT PROTECTION (FACE SHIELD OR GOGGLES)
DO NOT POINT THE AIRFLOW AT YOURSELF OR OTHER PERSONS
DO NOT LET THE PRESSURE BE MORE THAN 30 PSIG (200 KPA).

LOOSE PARTICLES AND/OR HIGH PRESSURE AIR CAN CAUSE INJURY.

CAUTION: BE CAREFUL NOT TO CUT INTO THE METAL OF THE FRAME WHEN YOU DO THE GRINDING. DAMAGE TO THE PART CAN OCCUR.

(1) If the pin was installed, replace it with a new pin.
(a) Do the counterboring of the stop pin with the locally manufactured tool.
(b) Loosen and remove the stud. Discard it.
(c) Do an inspection of the pin hole with a gage.
(2) If no pin was installed, remove the defective studs from the aft face of the inner hub as follows:
(a) Remove the tack weld which safeties the defective stud to the frame. To do this, use a small, narrow grinding wheel.
(b) Loosen and remove the stud. Discard it.
(c) Complete the removal of the remaining tack weld material with a small manual grinding tool and grind the tack weld beads to have a continuous surface with the adjacent areas. Refer to CFM SPM 70-41-12-350-010.
(d) Blow the areas adjacent to the hole for the stud with shop air.
(e) Do the fluorescent-penetrant inspection of the machined area on the turbine frame. Refer to CFM SPM 70-32-00-230-001. Use S2 sensibility. Cracks are not permitted.
(3) Do an inspection of the tapped hole with a gage. Indications are not permitted. If there is any indication in the tapped hole, this repair is not applicable to the part.
(4) Apply a thin layer of graphite grease (Material No.CP2101) on the stud threads which go in the hole of the frame.

PRE CFM SB 72-0368

(5) Tighten the new stud by hand on the turbine frame. Then use a torque-wrench to complete the installation. TORQUE the stud to between 270.0 and 244.0 lbf.in (3.05 and 2.76 m.daN )

. Refer to CFM SPM 70-70-11-400-002.
(6) Loosen the stud and TORQUE it a second time to between 270.0 and 244.0 lbf.in (3.05 and 2.76 m.daN )

.

END of PRE CFM SB 72-0368

POST CFM SB 72-0368

(7) Tighten the new stud by hand on the turbine frame. Then use a torque-wrench to complete the installation. TORQUE the stud to between 558 and 505 lbf.in (6.31 and 5.71 m.daN )

. Refer to CFM SPM 70-70-11-400-002.
(8) Loosen the stud and TORQUE it a second time to between 558 and 505 lbf.in (6.31 and 5.71 m.daN )

.

END of POST CFM SB 72-0368

(9) Machining of the pin and the pin hole

WARNING: USE PERSONAL PROTECTION EQUIPMENT. METAL PARTICLES CAN CAUSE DAMAGE, INJURY OR IRRITATION.

(a) Machine the pin hole with the locally manufactured tool. Refer to CFM SPM 70-44-50-320-006.
(b) Machine the locally manufactured pin. Refer to CFM SPM 70-44-00-320-001.

NOTE: The pin must be machined in relation to the pin hole to have a tightening of 0.0008 to 0.0012 in. (0,02 to 0,03 mm) minimum.

(10) Install the pin and grind the pin flush with the flange of the stud with the locally manufactured tool.

NOTE: If there is bushing, put the new stop pin at 0.394 in. (10 mm) minimum from the existing stop pin.

(11) Apply a thin layer of graphite grease (Material No.CP2101) on the bolts which secure the thermal insulation blankets.

PRE CFM SB 72-247

(12) Re-install the two adjacent thermal insulation blankets with attachment bolts on the rear flange.

END of PRE CFM SB 72-247

POST CFM SB 72-247

(13) Re-install the two adjacent thermal insulation blankets with washers and attachment bolts on the rear flange.

END of POST CFM SB 72-247

(14) TORQUE the bolts to between 110 and 100 lbf.in (1.24 and 1.13 m.daN )

5. Close-up
Subtask 72-56-00-410-065-A ** ON A/C NOT FOR ALL

A. Close Access
(1) Install the centerbody (Ref. AMM TASK 78-11-12-400-041).
(2) Install the core nozzle (Ref. AMM TASK 78-11-11-400-041).

[Rev.10 from 2021] 2026.04.01 13:00:19 UTC