Thanks for the link to the manual. As I replaced the elevating shaft, I am certain that the washers were/are present. However, that doesn't mean that when they went in, or since the install that something caused a failure or degradation of the washers. I will indeed reinstall the entire antennae and see what happens after that. The seal all around the base looks good, does not move or pull up and has stuck to the metal at least all alone the topside that I can see.
Sorry to hear that your unit has been so problematic, at least you are capable and handy enough to deal with much of it yourself.
It amazes me to hear so many stories about dealers in this industry not doing their job and taking care of customers post-sale. Makes me glad I did not purchase from a dealer. I have been fortunate to have found an independent RV service company (mobile as well) that is outstanding in every way. I've learned a lot since becoming an RV owner but still have much to learn, it's nice to feel comfortable calling on someone I can trust.