A planetary wheel end assembly comprising: an axle shaft defining an axis of rotation, said axle shaft having an inboard end and an outboard end; a planetary gear assembly including a sun gear driven by said axle shaft, a plurality of planet gears in meshing engagement with said sun gear, a non-rotating ring gear in meshing engagement with said plurality of planet gears, and a planetary spider supporting said planet gears, said planetary spider providing a driving output to rotate a wheel component; and a rotational support element positioned radially between said outboard end of said axle shaft and said planetary spider to allow relative rotation between said planetary spider and said outboard end of said axle shaft, wherein said rotational support element comprises one of a bearing or a bushing; and a shaft sleeve surrounding said axle shaft, said shaft sleeve having an inboard sleeve end and an outboard sleeve end with said outboard end of said axle shaft extending outboard of said outboard sleeve end of said shaft sleeve, and wherein said shaft sleeve is fixed for rotation with said axle shaft about said axis of rotation, and wherein said sun gear is fixed for rotation with said shaft sleeve, and wherein said outboard end of said axle shaft extends outwardly of said shaft sleeve and into a bore formed in an inboard end face of said planetary spider; and characterised in that said sun gear and said shaft sleeve are separate components that are fixed to each other, and in that the planetary wheel end assembly further comprises a wet disc brake enclosed within an inboard end portion of a housing, and the wet disc brake includes an actuator housing, a brake housing, a plurality of stationary discs that are fixed to the brake housing and a plurality of rotating discs that are fixed for rotation with the axle shaft. an axle shaft defining an axis of rotation, said axle shaft having an inboard end and an outboard end; a planetary gear assembly including a sun gear driven by said axle shaft, a plurality of planet gears in meshing engagement with said sun gear, a non-rotating ring gear in meshing engagement with said plurality of planet gears, and a planetary spider supporting said planet gears, said planetary spider providing a driving output to rotate a wheel component; and a rotational support element positioned radially between said outboard end of said axle shaft and said planetary spider to allow relative rotation between said planetary spider and said outboard end of said axle shaft, wherein said rotational support element comprises one of a bearing or a bushing; and a shaft sleeve surrounding said axle shaft, said shaft sleeve having an inboard sleeve end and an outboard sleeve end with said outboard end of said axle shaft extending outboard of said outboard sleeve end of said shaft sleeve, and wherein said shaft sleeve is fixed for rotation with said axle shaft about said axis of rotation, and wherein said sun gear is fixed for rotation with said shaft sleeve, and wherein said outboard end of said axle shaft extends outwardly of said shaft sleeve and into a bore formed in an inboard end face of said planetary spider; and characterised in that said sun gear and said shaft sleeve are separate components that are fixed to each other, and in that the planetary wheel end assembly further comprises a wet disc brake enclosed within an inboard end portion of a housing, and the wet disc brake includes an actuator housing, a brake housing, a plurality of stationary discs that are fixed to the brake housing and a plurality of rotating discs that are fixed for rotation with the axle shaft.