Thin pavement, overloaded trucks and a little water do wonders for the RV's rattling, you never see a truck scale on any road in Mexico, why do you think that there are so many road gator's on the roads.
Watch the fist class passenger buses they normally go on the left lane, less holes and smoother pavement, until you get the tope.
A lot of the libre "free" are far better maintained than the cuota "toll", I have asked the toll booth attendants if I am paying for all of the holes and just a little of the pavement, they just look at me and hand me the change.
navegator