Hi NJRonbo. I think there may be some confusion out there as to what a TSB is and what it means when others speak of a TSB "covering" certain vehicles, model years etc. Action explained it well. In the vast majority of cases, TSB's do not affect or extend our 4 year/50,000 mile New Vehicle Warranty or 6 year/70,000 mile Powertrain Warranty.
A new vehicle is covered under warranty, and we don't need a TSB to have a problem corrected and covered under warranty.
A simple explanation: TSB's can address various issues in various ways. For example...In cases like a rocking seat issue, a TSB simply tells the Dealership/Tech (a simplified explanation...lol),"We have seen this issue previously and know what the problem is and now know what caused it. So to save yourself time and effort, here is the solution, what to do, the parts you may need, etc...".
In this way, the Service Department does not waste time trying to figure out what is wrong, what is the cause, how do we solve it, what parts to order if necessary, etc. etc. The TSB tells them what the underlying cause is, what to do to fix it, how to do it, what parts to order, etc. etc. In this way, Ford saves on warranty costs, the Dealership saves time, and paying customers hopefully save money too.
As far as what models and model years a TSB covers: The "covered models/model years" (and sometimes down to a month/day of production) simply means that a particular issue was found to be relatively prevalent in those models and model years, up until the underlying issue was discovered and corrected on the assembly line. Could have been due to a bad patch of parts, an improperly working robot, a faulty tool, a sloppy assembly line worker etc.
In the case of a rocking seat (I'm making this up)...It could have been due to a improperly calibrated torque wrench which did not tighten down the seat bolts properly for 6 months (make up any number), until it was discovered and fixed. So now the owners of those vehicles which were made during that 6 month period are experiencing the problem and Dealers are reporting a lot of loose seats. So Lincoln issues a TSB explaining that they have seen this issue and here is how to fix it quickly and easily. Again, that is just a simplified explanation.
And again, if a vehicle is still covered under the New Vehicle Warranty, all work like this is covered, TSB or not. So always bring a vehicle in to the Dealership for service work if you have issues under warranty.
Hope this is somewhat understandable, and good luck.