Correction Procedures - TB-1-1520-240-20-1230003

TB 1-1520-240-20-123

NOTE

Disassembly is not required for visual inspection.

NOTE

The seal is made up of two separate halves around each rotor shaft.

Each half needs to be inspected.

For seal assemblies that are installed on the aircraft --

(1) Gain access to the slider shaft --

(a) Aft Slider Seal Assembly -- TM 55--1520--240--23P, Figure 199, Item 203, or TM

1--1520--252--23P, Figure 6--25, Item 194.

(b) Forward Slider Seal Assembly -- TM 55--1520--240--23P, Figure 179, Item 33, or TM

1--1520--252--23P, Figure 6--2, Item 33.

(2) Using a flashlight and inspection mirror, locate the dust seal on top of the slider shaft and verify

that the rubber seal overlaps the inside edge of the metal base.

(3) Perform the inspection procedures in accordance with Task 6--58, Step 7 of TM

55--1520--240--23, or Task 6--68, Step 7 of TM 1--1520--252--23.

(4) If the inside diameter of the rubber seal extends beyond the inside edge of the metal base

in accordance with 8A (2), and meets the clearances specified in accordance with 8A (3), the inspection of

the aft seal is complete.

(5) If the inside diameter of the rubber is found to be even with the inside diameter of the metal

base, proceed to paragraph 8B.

If the seal assembly around the aft or forward rotor shaft is found defective --

(1) Remove the seal assembly. To gain adequate access to the seal assembly it may be neces-

sary to first remove the rotor head and rain shield (C/MH--47D -- TM 55--1520--240--23, Chapters 5 and 6,

and MH--47E -- TM 1--1520--252--23, Chapters 5 and 6).

(2) Remove the seal from the slider shaft.

(3) Inspect the vertical rotor shaft for any damage that may have been caused as a result of the

defective seal.

(a) If damage is found to the vertical rotor shaft, contact the technical point of contact in para-

(b) If no damage is found to the vertical rotor shaft, proceed to paragraph 9.

For seal assemblies not installed on the aircraft --

(1) Identify all seal assemblies with cage code 59213.

(2) Perform a visual inspection to ensure the inside diameter of the rubber extends past the inside

diameter of the metal base.

(a) The inside diameter of the metal base should measure 7.5 inches and the inside diameter

of the rubber should extend beyond the inside diameter of the metal base by at least 0.375 inches.

(b) If the seal falls within these parameters, the inspection of the seal is complete.

Correction Procedures. If a Seal Assembly is found to be defective --

Replace the seal with a properly manufactured seal and reassemble.

b. If no seals are available, send the seal to the AVIM support facility where the seal assembly can

be reworked to the proper specifications. Notify the logistal point of contact in paragraph 16B who will forward

the technical drawings to the LAR.