TB-9-2350-277-40&P-4 M121 M1064A3 Crew Modification Kit Volume 4 Download
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TB 9-2350-277-40&P-4 MODIFICATION PROCEDURES – Continued 0004 00 0004 00-4 NOTE The 3-9/16 inch hole in the magnetic drill base plate/template must align with 3-1/2 inch hole previously marked on hull roof. Minor adjustments to position magnetic drill base plate/template may be necessary. 2. Position magnetic drill base plate/template (6) on rear hull roof. Measure 6-3/4 inches from the rear edge of hull (3). Measure 37-3/32 inches from the right hull edge (5). NOTE The magnetic drill base plate/template is 1 inch thick. Marking the drill for a maximum depth of 2-1/4 inches will prevent any break thru. 3. Drill four holes (7) using a 5/16 inch drill bit to a maximum depth of 1-1/4 inches. DO NOT BREAK THRU. 4. Drill a pilot hole (8) using a 1/4 inch drill bit and magnetic drilling machine. 5. Drill center hole (4) using a 3-1/2 inch saw drill bit and magnetic drilling machine. 6. Tap four holes (7) using a 3/8 x 16 tap. Tap holes to a minimum depth of 7/8 inch. Figure 3. Location for CREW II Cover Plate 7. Paint drilled area to prevent corrosion. Reference TM 43-0139.