When my doors start squeaking and opening/closing hard, I just spray the hinges with WD-40. It will last for about a month, then need spraying again. We use our camper full time. So the doors get used many, many times every day. It workes.
Actually, the "friction" is not so great any more (maybe too much WD-40). When the wind blows, the doors slam shut. So, I finally installed the old-fashioned door catches on the side of the camper for each door. I hook the doors now when we want them open. Wind is no problem any more!
I agree, those doors were a good idea, but a bad design.
2019 Montana High Country 375FL
2014 Chevy Duramax HD 6.6 - 3500 Diesel Dully Long bed Crew Cab