it is not a common practice, in fact, in order for a spring to break, you need to be doing a lot of very rough driving, daily and frequently, and even then a spring won't go bad.
maybe after 20 years they might start to sag a little big, but do not let them push you into replacing them.
don't let them pull a line like they aren't compressing at the right whatever, it's all bunk and designed to make you pay more for something you don't need.
In fact, you should have your shocks replaced somewhere else, so you won't pay as much,and you will get a higher quality shock.
I recommend going with KYB GR-2, which will give you an upgraded ride from the original equipment, you won't be disappointed with them.
If you tow or haul a lot, or drive fast, take corners fast, etc.. go with gas-a-just shocks. they're a bit stiffer and will give better handling with those characteristics.
they cost less than the dealership shocks, and have a lifetime warranty, as well as getting much more bang for your buck.
If anything, find them at a local auto parts store, and goto a tire shop, like Big-O or wheel works, for instance, they'll install them for a lot less, as shocks are very easy to replace, and require very little labor, unlike struts.
Your Explorer does not have struts and does NOT need an alignment afterwards, although having an alignment once a year is recommended.
Stay away from Monroe shocks, they're ok shocks, they just don't last as long as they used to and don't give the ride they used to.
Gabriel is good, you can get those from autozone, get the middle shock if you go with these, they also have a lifetime warranty.
The dealership simply wants you to spend more money and they are getting creative in finding ways to do that.
