wow, just signed up and was browsing when i seen these postings. i believe the guy who pointed out that leveling jacks as per the (manufacture) state clearly they are not for lifting laid it out pretty clear! i work at a hd truck and trailer shop and we do a ton of rv sus and frame work including re-working frames to accomodate stress and we (as a rule) never lift from front to back as
most modern frames are made from 16 gauge 12 guage max material and never (t100) their for they (will) flex and if you have a hardwall trailer you will cause damage maybe not today maybe not tommorow but it will happen. if your changing a flat the best rule is to jack as close to the inside of the wheel as possible and if their is no lifting points use a block of wood to help prevent dammage to the axel tube. usng your stabalizers as a safty measure is not a bad idea. i cracked the wall of my tin sided pioneer 180ck by doing just that and it was much more rigid then whats out their now.