From Mark Jones:
What shock mounts can I use on my A23A? It has the floating instrument panel. I seem to have three upper mounts with brass studs and four lower mounts with steel studs.
Search strings: panel mounts, floating mounts, instrument mounts, floating panel, Lord mounts
Technical Editor:
The cushion mounts for the floating panel are always supposed to have brass studs, to reduce the possibility of magnetic interference with indicators and compass.
The original part number was J6984-60; this is a Lord mount number, which makes it a ‘standard hardware part’. It has 8-32 threads on 1/4″ long brass studs. Beech no longer stocks the original mounts. They show an optional supersedure to part number 169-324000-35, at a price of $235 each. That’s just nuts.
With some guidance, Mark has been able to compile the following information, to help out fellow members. The short story is that you can order the J-6984-8, Spruce part number 10-14700. The current price is $5.75 each. You just need to trim 1/8″ off the brass stud on each end. The -8 was commonly used on Cessnas. Here is a link to the Spruce page for these mounts:
http://www.aircraftspruce.com/catalog/inpages/shockmounts3.php
The same mount is available from Chief Aircraft under their part number LD_J6984-8. This reinforces my belief that the remaining supply is probably New Old Stock; and that any new manufacture (when the current stock is exhausted) will likely be ten times the price. If you do a search on Chief, search only on ‘J6984-8’. Be careful not to select the version with steel threads (a different brand name). Here is a link for Chief:
http://www.chiefaircraft.com/airsec/Aircraft/InstallationSupply/ShockMounts.html
If you have one of the earlier planes with the floating instrument panel, and your panel mounts are the least bit deteriorated, I would order a set right now. These are most likely New Old Stock from a surplus lot, at this price. When they run out the price will quite likely go over $50, based on current Lord parts pricing elsewhere, for similar parts.
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Mark Jones:
Technical Support cleared it all up for me. There are 3 shock mount numbers which are exactly the same with the exception of the length of the studs. The J-6984-60 has 1/4 inch brass studs on both ends. The J-6984-64 has a 1/4 inch long brass stud on one end, and a 3/8 inch long brass stud on the other end. The J-6984-8 has a 3/8 inch long brass stud on both ends. The threads are 8/32 on all 3, and the rubber composition and size is also the same on all 3. Therefore to match the original J-6984-60 the other 2 types merely need the studs trimmed off. Spruce does not have in stock the J-6984-64 but they do have in stock the J-6984-8, Spruce part number 10-14700 on page 413 of the 2008-2009 catalog. The price in the catalog shows $7.35 but this is wrong. The actual price is $5.75 each. I ordered 7 of them and will trim the studs as needed to fit the brass acorn nuts on the instrument panel. Most good-quality electrical terminal crimpers have threaded holes, which work perfectly for neatly trimming the threaded brass studs.
Hope this info may help someone else whose mounts are stiff and/or broken. I’m sure the Gyro instruments in my panel will have less vibration effects with these new mounts.
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Be sure to thank Mark for his efforts, when you see him!