. A landing gear axle comprising: an inner journal comprising a section of the landing gear axle that is configured to receive an inner portion of a wheel; an outer journal comprising a section of the landing gear axle that is configured to receive an outer portion of the wheel; a mid-journal section comprising an annular surface of the landing gear axle, axially between the inner journal and the outer journal and having a radius less than a radius of the inner journal and less than a radius of the outer journal; and an axle sleeve (10, 10a) disposed over the mid-journal section, the axle sleeve comprising: a main body; and an expansion mechanism whereby a diameter of the main body may be varied, wherein the expansion mechanism comprises a helical cutout arrangement comprising: an inner helical cutout comprising a slit defined through the main body and extending helically from an inner edge of the main body; an outer helical cutout comprising a slit defined through the main body and extending helically from an outer edge of the main body; an inner edge remaining portion comprising an annular section of the main body unbroken by the inner helical cutout; and an outer edge remaining portion comprising an annular section of the main body unbroken by the outer helical cutout, and wherein the inner helical cutout extends at a first spiral angle relative to the axle sleeve (10, 10a), wherein the outer helical cutout extends at a second spiral angle relative to the axle sleeve (10, 10a), and wherein the main body comprises a cylinder section; and wherein the axle sleeve comprises a material that is softer than the axle. an inner journal comprising a section of the landing gear axle that is configured to receive an inner portion of a wheel; an outer journal comprising a section of the landing gear axle that is configured to receive an outer portion of the wheel; a mid-journal section comprising an annular surface of the landing gear axle, axially between the inner journal and the outer journal and having a radius less than a radius of the inner journal and less than a radius of the outer journal; and an axle sleeve (10, 10a) disposed over the mid-journal section, the axle sleeve comprising: a main body; and an expansion mechanism whereby a diameter of the main body may be varied, wherein the expansion mechanism comprises a helical cutout arrangement comprising: an inner helical cutout comprising a slit defined through the main body and extending helically from an inner edge of the main body; an outer helical cutout comprising a slit defined through the main body and extending helically from an outer edge of the main body; an inner edge remaining portion comprising an annular section of the main body unbroken by the inner helical cutout; and an outer edge remaining portion comprising an annular section of the main body unbroken by the outer helical cutout, and wherein the inner helical cutout extends at a first spiral angle relative to the axle sleeve (10, 10a), wherein the outer helical cutout extends at a second spiral angle relative to the axle sleeve (10, 10a), and wherein the main body comprises a cylinder section; and wherein the axle sleeve comprises a material that is softer than the axle. a main body; and an expansion mechanism whereby a diameter of the main body may be varied, wherein the expansion mechanism comprises a helical cutout arrangement comprising: an inner helical cutout comprising a slit defined through the main body and extending helically from an inner edge of the main body; an outer helical cutout comprising a slit defined through the main body and extending helically from an outer edge of the main body; an inner edge remaining portion comprising an annular section of the main body unbroken by the inner helical cutout; and an outer edge remaining portion comprising an annular section of the main body unbroken by the outer helical cutout, and wherein the inner helical cutout extends at a first spiral angle relative to the axle sleeve (10, 10a), wherein the outer helical cutout extends at a second spiral angle relative to the axle sleeve (10, 10a), and an inner helical cutout comprising a slit defined through the main body and extending helically from an inner edge of the main body; an outer helical cutout comprising a slit defined through the main body and extending helically from an outer edge of the main body; an inner edge remaining portion comprising an annular section of the main body unbroken by the inner helical cutout; and an outer edge remaining portion comprising an annular section of the main body unbroken by the outer helical cutout, and wherein the inner helical cutout extends at a first spiral angle relative to the axle sleeve (10, 10a), wherein the outer helical cutout extends at a second spiral angle relative to the axle sleeve (10, 10a), and wherein the main body comprises a cylinder section; and wherein the axle sleeve comprises a material that is softer than the axle.