Looking at class c questions on maintenance

Depends on the dealer. The ford dealer in my town will not do any kind of work on RV's including tires. Check with your local dealer.

the dealer i go to will do some work on a C but not an A there lift can only hold 15k lbs. so they wont krall under under it

Call around to your chassis dealers of choice, and ask before you buy. When we had a Roadtrek in a Chevy Express van, the local GM dealer had no problem working on it. When we upsized to the Sunstar 26HE, we had to get the oil changed at a truck stop. Pricing was similar to the cost of a regular oil change, but they had a larger bay area to work on it. Our class C Navion on a Sprinter cab chassis gets it's maintenance work done at a nearby (120 miles round trip) MB dealer that sells Sprinter vans, and they have a hoist that can lift it.
Also, because they say they'll work on it now, doesn't mean that position can't change.
It's a problem for many motorhome owners these days.

Ford or GM dealerships often do not work on trucks or rvs due to garage bay size limitations.
Any car service station , doesn't have to be a Ford or GM dealership, will be able to perform most services and repairs 'out of doors' if weather is permitting. If its a Ford or GM, its a just a van chassis which is high enough off the ground to crawl under for oil service.
You won't be paying a commercial truck shop labor rate either.
Some commercial shops now are in the $200/hr range and put rv recreational folks second on their 'priority list'. They take care of repeat service contract commercial accounts, where guys need trucks to earn a living before they take of rv people that use their rigs for playtime. That has been made clear to me more than once.

Unless there is some sort of coupon, the last place I would consider is a dealer for an oil change.

If you have a good local shop you trust, that would be my preferred (and what we do when local for the truck).

Even most oil change shops are fine. They may need to do it in the lot if you don't fit in the bay but for an oil change, it's not rocket science and they don't need a lift.
- If you don't trust them, pay attention to what they are doing and check the plug, filter and oil level before pulling out...if those are all good it should be fine.

If it's major work, then you probably have to call around to see who can work on it.

Not an issue or concern. Same as changing the oil in any other gas motor. If one shop won't do it and you cant do it yourself, go to the next place.

The Ford dealer near our lakeside cottage in upstate NY not only services RV's, they have a separate building specifically for RV service and body work. That said, we've found truck shops to be much better choices for our chassis work needs. I still do my own oil changes and chassis lube though.

Dealers would be my last choice!
Oil change and lube joints and even Walmart would be better choices.

My Tiger Class C, 20 feet long, on a stock 2500 HD 4x4 chassis, goes to the Chevy dealer work truck department for all of its basic fluids, changes, belts, etc. This dealer has all the parts, offers a shuttle service, and has done a great job for the 16 years I've had this truck. The mechanics love it; they say they've never seen anything so cool on a Chevy chassis.

For something that can be done in your driveway I would not rule out a mobile mechanic. Look up RV mobile mechanics and check their

pricing. A dealer would be my last choice for anything. There is nothing special about these chassis, be it Ford GM or otherwise. Now a

MB chassis will cost more due to those two letters.