REPLACE SCREW-THREAD INSERT (AVIM) (Continued)

TM 55-1520-240-23-1 1-16 REPLACE SCREW-THREAD INSERT (AVIM) (Continued) 1-16 NOTE Procedure is same to replace any screw-thread insert. Typical insert shown. For more information on screw-thread inserts, refer to TM 43-0104. 1. Cover openings in housing (1) in area of insert (2). Use barrier material (E80) and tape (E388). NOTE Use drill press if possible. 2. Install drill bit in drill or drill press. Use 5/16 inch drill for inserts MS51991-206 and MS51991-206L. Use 29/64 inch drill for insert MS51991-208. 3. Measure and record thickness of replacement lock ring (3). NOTE Interlock need not be drilled away to full depth. Three-quarters depth is enough. 4. Cut away interlock area (4) between insert (2) and lock ring (3) by drilling through center of insert. Do not drill deeper than lock ring thickness recorded in step 3. Use several light cuts. Pull back drill between cuts to clear chips and check depth. NOTE As insert comes out, it will lift out remaining part of lock ring. If it does not, use punch to collapse and remove remaining part of ring. 5. Turn and remove insert (2) and remaining part of lock ring (3) from housing (1). Use screw extractor. 1-28