If you have an old upright piano in your household, the chances are the wheels or casters will at some point need replaced. While it might seem that an upright piano would be lightweight enough to replace its wheels with ease, you'll be surprised at how challenging it can be. Once the piano is in position, though, replacing the wheels themselves requires only moderate skills and a couple of tricky manoeuvres.
Lay down two 2x4 boards on the floor that you'll use to rest the upright piano on its back.
Get two other strong people to help you set the piano on its back. Check to make sure the side of the piano is resting on the boards.
Understand that placing the piano in this position will allow the new wheels on the piano to have support, so the piano doesn't start rolling the minute it's placed back on the floor.
Inspect the existing wheels.
Take a screwdriver and remove the screws from the socket plate on each caster. You may find that the casters are filled with dirt and dust from years of use or while sitting in storage. Discard them, because they won't be reused.
Know that some of the original screws holding the casters in place may be too old and will need to be replaced. Buy new screws that are a little longer, but no more than ½ inch long. Keep in mind that general purpose casters may not fit the sockets of old upright pianos. Buy special rubber casters with wooden grommets (see Resource 1) to help get them easier into the older caster sockets.
Use a power drill or manually screw the new screws into the caster sockets. Be careful not to force them in if they don't go in smoothly to the aged wood.
Deepen the socket holes if the casters still don't go in correctly.
Make sure the socket plate is on securely before inserting new caster wheels. Use a hammer to tap the casters in.
Spin the wheels around after inserting them into the socket holes to make sure they don't catch on the wood surface under the piano. Rout out the wood around the area if the wheels rub up against the wood and can't rotate.
Apply some light oil to the joints of the wheels to make the casters roll easier once the piano is upright.
Have your helpers help you lift the piano back up. Make sure the 2x4 boards underneath are still providing support to keep the piano from rolling away. Then remove them.
Some caster sockets on old upright pianos have only three holes, but newer sockets have four. Drilling new holes to make the replacement casters fit may be a separate challenge beyond the scope of this article.