pebald,
I am glad to hear that you did NOT purchase a Kubota!!! Seriously, I like Kubota's fine. You have gotten a tractor which is highly anomalous for a JD. JD has had some batches of bad O rings, as do all manufacturers from time to time. They will make things right for you. It sounds as though you have a good dealer, but sometimes the dealer and the regional rep are not on great terms, or the regional rep might be just poor. The problem I see here is the mixed messaging that might be occurring. Our tendency is to take things to the top and it sometimes confuses the issue or circumvents the natural process of things. Having owned over twenty pieces of JD machinery I have had great luck with the brand, including two 3720's, a similar sized machine to what you currently have. I have had some trouble with a Gator I owned, (one of four) and my dealer picked it up ASAP and began work. It was a new machine and parts were at the time not widely available. The regional rep was involved but I went fully through my ONE contact at the dealer. He said the JD format is so dealer weighted, that the system does not work well when climbing the ladder. I would stick with your prime dealer contact and let him do what you paid him to do. He and his business depend on you being happy and most dealers want the best for their customers to maintain their good name and vye for future purchases. The 3320 is a great tractor, you happened to have purchased one with some major but repairable issues. I think if you stick with the dealer as your advocate and continue to use their loaner until yours is complete, you will be fine. I would not push for a new tractor, unless you just must have one to rid yourself of any bad taste. The 3320 will serve you well and you did make a good choice in tractors, you just haven't had a chance to realize it yet as you have not had your tractor.
I think the attorney idea is one I would not myself consider. To "threaten" legal action at a juncture such as this is not a wise move because who is going to service your tractor when it begins its true 30 year lifespan??? I doubt a dealer who has received an attorney's letter would do so. I would definitely not do that.
John M