Are both necessary?
Four wheel alignments are pretty much the norm these days. Some vehicles need adjustments made in the rear while others do not. Many shops have one set price, whether your vehicle calls for a two wheel alignment or four wheel alignment. If your vehicle has provisions for rear alignment, and needs adjustments, and you decline them for whatever reason, you could experience dog tracking, unusual tire wear, unusual handling, or other things.
Front and rear is normal…Especially on vehicles with independent rear suspension.
The Windstar does not have independent rear suspension.
In fact, it has a so-called “solid” axle/lateral beam connecting the rear wheels, and this component is prone to fracturing as a result of exposure to road salt. When it fractures, it almost always leads to severe handling problems, and several accidents have been attributed to this catastrophic failure.
I would suggest that, prior to doing any alignment work on this van, the OP should contact the service department at a Ford dealer, provide them with the VIN, and determine if this vehicle is one of the tens of thousands that have been recalled.
Why would you allow a mechanic to do any adjustment to the rear axle before finding out if that axle needs to be replaced–without cost–by Ford?
Thanks for the timely information. Our Windstar did “pass” the rear axle recall inspection, however, I need to take the vehicle in now for front subframe problem recall.