Shim and Wedge Installation.

TM 9-1270-212-14&P

with the pilot hole (step u of paragraph 5-10). In this case,

w. Secure the strap tabs inside the helmet and the back

drill a new hole in the back strap. Do not change the

straps of the helmet sight assembly, using the shortest

position of the hole in the helmet wall.

threaded pin (3, fig. B-2), a washer (2), and a pin collar (1)

on the right back strap and the next-to-shortest threaded

pin (5), loop clamp (4), a washer (2), and a pin collar (1) on

the left back strap. Be sure the cable clamp is positioned as

5-12. Installation of Previously Drilled Helmet Sight --

Assembly onto Previously Drilled SPH-4 Helmet.

x. Permanently tighten all the pin collars (installed in v

and w above).

Perform steps 5-10h through 5-10y. In step 5-10u, a new

NOTE

hole may have to be drilled in the back strap of the helmet

sight assembly. Do not change the position of the hole in

The pin collars are tightened by holding the

the helmet wall.

inner part of the threaded pin with a hex key

wrench while turning the outer part of the pin

collar until the outer part sheers off and only

the inner collar remains.

5-13. Shim and Wedge Installation.

y. Clean the metal filings and other debris from the

helmet.

If shim 2202214-00 and wedge 2202213-00 have been

5-11. Installation of previously Drilled Helmet Sight

installed on your helmet sight assembly, these items will

Assembly onto new SPH-4 Helmet.

have been installed as a set and must be maintained as a set.

If the shim and wedge are not installed, gasket 2251744-00

Perform the procedures of paragraph 5-10. The hole in

is required in place of the wedge. See Appendix B, figure

B-2.

the back strap of the helmet sight assembly may not line up

5-6