2004 John Deer Buck Utility ATV 500, 500EX and 500EXT Service Manual, Page 197Get this manual
Take the half housing with pinion gearMeasure distance between housing edge and the inner ring of bearingThis is measure "G" V04H07A
V04h07a2.EPS
Remove pinion gear then measure the distance between mount surface and bearing surfaceThis is measure "E"
V01H1DA
V01h1Da2.EPS
Measure the other half housing between housing edge and the inner ring of bearingThis is measure "H"
V04H08A