barmaid -
My experience is that some RV shops work on both house and chassis and some just the house. And there are other combinations too. Tomorrow I am getting two steer tires, front end alignment, and this shop does light chassis stuff like oil changes and lube. The advantage of going to a CAT or Cummins shop is that they hook up your motor to a computer and you get any of the latest upgrades to software. Frankly I have had mixed results. If you can get work done relatively close to where your home base is or you are going to be for a while that is a good thing. You can go see them easily when rework needs to be done. I have had several /a number of instances where I got something done on the road and 500 miles away the work bit me.
As far as chassis goes, make sure you get one that is long enough for the house. The shorter the overhang front and back the better. And also that the chassis has enough CCCs for you to carry all the stuff you want to. CAT and Cummins are very good motors in some models. But do a google check to make sure you get a good one. The high end Detroit diesels are also very good, but only in very high end coaches. What I mean by do a google check is google to see about problems on certain motor models or years.
Brakes are very very long lasting on DP coaches.
Tires usually age out before wearing out. Cost approx 500 bucks a tire for 22.5".
Usually good to do an eyeball check on serpentine belt every few months. This greatly aided if you have a side radiator. And if possible you do want a side radiator.
I have never had any problems with my auto level or electric steps. But other stuff. Like hydraulic slide mechanisms. And slides in general. Batteries or I should say getting repair shops to turn off all the coach electrics so they don't run the batteries down to zero and ruin them.
