The bias belted tires squirm less, run cooler, and give
H A - 1 3 2 1 , A / S 3 2 A - 3 1 A t o w t r a c t o r. ) R i m s
better mileage than the bias tire.
requiring NDI and meeting visual inspection are
paint stripped and subjected to magnetic particle or
liquid penetrant inspection. Personnel performing
NDI inspection must hold current certification
Radial tires are constructed with one to three plies
according to requirements of OPNAVINST 4790.2
of the body cords running at right angles to the
for MIL-STD-6866 and/or MIL-STD-1949
circumference. Over this radial section is added a belt,
or belts, of fabric or steel. The design provides a tire
with flexible sidewalls but great stiffness and strength
Removing and Replacing Tires
in the tread area. It has minimum squirm, runs cool,
and provides long wear.
The following procedures involve removing a
wheel from a vehicle, removing the tire from the rim,
putting the tire back on the rim, reinflating the tire, and
putting the wheel back on the vehicle.
Tubeless tires may be bias ply, bias belted, or
Use a "deflated tire flag" to show that a tire has
radial. In addition, they have a thin rubber lining, and
b e e n d e f l a t e d a n d t h e va l ve c o r e r e m ove d .
the bead area is grooved to form an airtight seal with
M a i n t e n a n c e s h o u l d n eve r b e c o n d u c t e d o n a
wheel/tire assembly where a deflated tire flag is not
Solid Rubber Tires
installed. The flag tells you that the tire is safe.
Deflated tire flags are usually made locally, and they
Solid rubber tires are used primarily on slow
are made so that the pin extends at least 1/4 inch
moving, heavy loading equipment. They provide far
beyond the open end of the valve cap, with the cap
less cushioning than pneumatic tires but give loading
shouldered against the pin.
capacity far greater than comparable sized pneumatic
Short deflated tire flag pins (less than 3/4 inch)
WHEEL AND TIRE MAINTENANCE
may enable the flag to be screwed on the valve
The types of wheel assemblies found on support
stem with the valve core still installed. Always
equipment are split rim, demountable flange, and
check to be sure that the core has been removed.
solid rim (automotive) types. Of the three types of
wheel assemblies, the demountable flange possesses
the highest potential for explosive separation.
REMOVING WHEEL ASSEMBLIES.--Use
the following steps for removing a wheel from a
The destructive potential of air, or nitrogen,
under pressure is tremendous. As an example of the
explosive force produced, a 10.00 x 20 tire inflated at
1. Chock both wheels at the end opposite the end
105 psig creates in excess of 40,000 pounds of
pressure against the rim flange. In a controlled test,
2. Jack the vehicle and place jack stands under the
this force accelerated the locking to 130 mph, and
frame or axle, as required by the technical
raised a 215-pound dummy 10 feet upward from a
manual. Lower the vehicle to the jack stands. If
wheel resting horizontally on the deck. This
aboard ship, install tie-down chains.
explosive potential requires that all inflated, or
3. Deflate the tire to be removed, remove the valve
partially inflated, tires be handled with the same care
core, and install a deflated tire flag (fig. 2-95). If
and precautions given live ordnance.
the valve stem is equipped with a valve
extension, remove the extension valve core and
extension first. Wheels being removed to
A nondestructive test/inspection (NDI) of split
facilitate other maintenance need only be
rim (steel) wheels and tie-bolts are required by
deflated to storage pressure, which is one-half
applicable periodic maintenance requirements cards
the service pressure or 15 psig, whichever is
(MRCs). (Example, front wheel assembly, P/N