SECTION II. EQUIPMENT DESCRIPTION AND DATA (Con't)
1-8. EQUIPMENT CHARACTERISTICS, CAPABILITIES, AND FEATURES (Con't).
i. RIM TYPES AND VARIATIONS (Con't).
(7) Earthmover Rims. Earthmover rims are used for extremely large tires. These rims may
be characterized by four demountable pieces, which include an inner rim base with non-demountable
flange, outer rim flange, bead seat band and a lockring. The rim base has a non-demountable rim
flange and 5º tapered bead seat. The outer flange and lockring secure the outer bead seat band to the
rim and tire. Between the rim base and bead seat band, a groove is provided for a rubber, preformed
packing that seal the rim and retains air. To prevent slippage between components some rims may
come with components that have a notch, driver lug and/or welded-on lug that lock the components
together. Also the rim manufacturer to further prevent slippage may knurl bead seat surfaces.
(8) Grader Rims. Grader rims are similar to three-piece flat-base rims except the rim bead
seat diameters are slightly less than those established for truck rims. For this reason, only grader tires
should be mounted on grader rims. Modern grader tires are tubeless with a rubber packing between the
outer flange and rim base to prevent leakage.
(9) Rim Variations. There are many variations of the previously described rims. A
semidrop-center rim may have both bead seats on the main part of the rim base, or the bead seat may
be on the removable flange. The flat-base rim may have a three-piece construction Removable rims
flanges may be mounted or demounted from the rim base with several nuts and studs instead of locked
in place with a lockring. Consult the vehicle Technical Manual for specific descriptions and
instructions on wheel/tire maintenance, as the rims described, only represent general construction
characteristics of rims.
LARGE EARTHMOVER RIM
Bead Seat Band
THREE-PIECE FLAT-BASE RIM
Outer Rim Flange