Mowermech: You are incorrect if we are talking about DP's. They have lots of grease fittings: tie rod ends, drag link, steering gear u joints and of course king pins. There are 2 fittings on each of my driveshaft u joints. Monaco recommends the u joints be greased every 5000 miles. I do mine twice a year. There are also grease fittings for the air brake shafts. DP's are not some puny chassis. They are very HD. Even if you have a late model gas chassis I would grease it more often than once a year. Grease is cheap. Parts are not.
Moisheh