in fact, most spindles are welded to the axle tube. Replacing a spindle requires breaking the existing weld and then welding the new spindle in place. Since welding axle components together probably falls outside of the comfort range of a lot of weekend mechanics, the installation of spindles in the typical homeowner's garage or driveway isn't very likely -- but it is possible.

By no means are we trying to discourage you from attempting a do-it-yourself installation of trailer axle spindles, but unless you're a skilled welder, this may be one of those jobs that are better left to the professionals. It's critical that spindles are properly aligned and secured to the axle. A licensed trailer repair facility should easily be able to install a new spindle or two. Remember, sometimes it may be worth the extra cost to save the time and frustration that can sometimes accompany a difficult (and unfamiliar) repair.