I haven't taken my rig on a long trip in 5 years. The last one was a nightmare. The truck blew a head gasket, the fridge quit working, the jacks would go up and down in the middle of the night all by themselves. Sometimes they wouldn't work at all. The TV came one all by itself at full volume in the middle of the night. I blew two tires within 100 miles. Both tires were less than a year old and had less than 8000 miles on them.
I'm going through my rig now to try to prepare. I had the truck engine bulletproofed for 8000 dollars. A year later I had it redone because the first shop didn't do any of the work they charged me for. I'm planning on getting new tires just before I leave and I'm replacing the jack switch. I'm going to have the RV shop pack the wheel bearings. Anything else I need to be concerned with?