I've used the pallet fork system with sledge hammer, don't have access to jack hammer. It works on most but not all. Also have used two small jacks hooked up to porta power units, that works most of time also. Priced shafts, they were around a 100 dollars, so tough ones just took a cutting torch to. Spacers are also available. Remember our time is worth a little. After market pillar blocks and bearings, with triple seals are available. Use anti-seize when putting together. As far as trading it off its hard to beat a 5000 with 550 trips if properly maintained, have had mine for 15 years, just replaced blockage monitor with Ag Tron system. Industry still has some bugs to work out on independent opener assembly controlled by its own hydraulic cylinder