For the most part, I do maintenance things myself. The E series chassis is not really difficult to work on; there's reasonable access to most things you need to get at on a regular basis, and it's not so heavy duty that you need unusual tools.
Chassis lube is four steering tie rod ends and the ball joints if they have grease fittings. Check the manual, but there's a good chance the differential has synthetic lubricant that does not have a scheduled periodic replacement (changing only required if you drive through water deep enough to submerge the differential).
When it's something more than I am able to or care to tackle myself, I take it to a local independent truck shop. I'm pretty sure Bailey Spring and Chassis doesn't have branch near Houston.
