I was thinking about the same thing. Did some checking here in Tucson and replacing all the seals, new bearings and changing from 3:73 to 4:30 were going to cost 1600.00 and that was for 2 axles, We have a 4x4.. Also don't forget to recalibrate the speedometer.
2011 jayco 33rlds, 2002 Ford excursion, v-10, 3:73 gears 4x4 mine. 2008 Suzuki sx-4, hers. Retired Air Force, now Retired.