Registered Piano Technician

Pianos are such noble instruments - they're either upright or grand.

Author Unknown

Super Service Call for Grand Pianos

I will need to estimate the cost. It can take 2 to 3 days to do the work.

May have left off a few items but the following will give some idea of the basics.  Key leveling and setting the keydip is checked and corrected as needed.  The hammer height is set and reset as needed. The order of work specified can vary.

1. Reshape hammers, travel shanks, space to the strings and fit to the strings.

The following photo shows some Mason Hamlin grand hammers before filing.



Most grand pianos in the field need this work. There is a point at which it is better to replace the hammers than to reshape them. I will determine that when I am there tuning the piano. The above hammers were worth filing.  It has been said that 40% of a piano’s tone is due to the hammers.  There is tonal loss due to the grooves in the hammers and that loss is proportionate to depth of the grooves. Reshaping of the hammers will produce a more pleasant tone in most cases.  If the basic hammer is extremely hard, then the tone may be brighter than before the filing. Needling of the hammers is usually required anyway. If the hammers are very hard, then more
needling is needed. On some Asian pianos I have used a mixture of alcohol and fabric softener to make the tone less harsh. It would require a tremendous amount of needling to get the same results on that type of hammer.

The following pic shows the Mason Hamlin hammers after I filed them.  The tone is a lot better.


2. Space the repetition levers on the whippens to the hammer knuckles.

Smooth up the knuckles using the appropriate grit sandpaper or use a brush. The hammer knuckles get wear marks which need to be removed when spacing the whippens or whenever they start getting prominent. Worn knuckles also contribute to the “clunker piano syndrome”.

Notice the white arrow poining to one of the worn knuckles in the picture above. The indentations are caused by the jack which rubs across the knuckle each time a key is depressed.

3. Tighten the action screws.

This includes the hammer flange screws and the whippen flange screws. The whippen flange screws are the ones that seem to be the most neglected. That is because the action has to be reversed or removed to access them well. Loose action screws also contribute to the “clunker effect”. The main action screws that hold down the action rails are tightened as well as those that hold down the action brackets.

4. Regulate the let-off and drop screws. Prior to this the an approximate hammer height will need to be set.

Yamaha Corp. specifies a let-off of 2mm in the middle section whereas Steinway recommends a closer let-off distance. Let-off is the point at which the hammer releases prior to striking the string. Regulate the back checks. Even up the hammer height. Poorly regulated pianos also cause the “clunker piano syndrome”.

5. I clean off the plain wire strings,  clean off the soundboard, tuning pin area and damper heads. I also vacuum under the keyframe.

Since most grand pianos have a una corde pedal, the keyframes must be free to shift to one side. Objects that are often found under keyframes are paper clips, pencils, coins, hair pins and a lot of dirt and grime. The keybed must be free of these type items. Trying to use the una corde pedal with objects present can cause the keyframe to not shift completely or get stuck in the shifted position. If you don’t feel the keyframe or keys return after using the una corde pedal, then you should have the piano serviced to determine the cause.

In the following picture the keyframe is lifted upward to show various items that were under it; I had already vacuumed out the dirt. I lubricate the glide bolts,  the action return spring and certain areas of the keybed with teflon powder.

7. Raise or lower the pitch and tune at A440 or slightly above in some situations.

8. Needle the hammers to get the tone even and at the required level of brightness or mellowness.

People have different concepts of the type of tone that they want. I like the treble to be bright. Otherwise I prefer the piano have a big and mellow type tone. 

There are other items that are not included here.

The action pinning can be loose for various reasons. The action flanges can be repinned to give the proper tightness. If the various parts are sluggish or pinned too tightly, I may try using Protek lubricant. There may be situations where it would be best to use a shrinking solution of alcohol and water. 

Contact Details

Yonley's Piano Tuning and Repair
1201 Eastside Dr.
Mesquite , Tx , 75149