Instrument Panel Shock Mounts

[8233]

I've had a couple of the panel shock mounts break on my 46 C120. I looked in the IPC and it lists PN of A301 and then also says Cessna Print 0411059.

I am having a tough time finding A301. What does that print number actually mean in the IPC? When I Google that print number, I get a shock mount most commonly listed as 0411059-1. It looks like a Cessna shock mount but lists it for the C150 on various online sites.

My IA is being anal and doesn't work on a lot of vintage aircraft. He says the print number doesn't matter and the -1 also makes a difference. Can someone tell me what the correct PN should be or if you know if it has been superseded? He also is insisting the mounts are different for the 120 and 140 and my IPC does not show that to be true for 1946 models at least.

If anyone has any thoughts or suggestions, I would appreciate it. I'm frustrated that I am in this debate with him. Trying to get back in the air asap.

Thanks

[5557]

Dave -

I replaced all four shock mounts on my 46 120 and got them from Univair. Almost certain the PMA and they weren't very pricey. My IA was happy with them.

Tom Macdonald

[VIP620]

https://www.aircraftspruce.com/catalog/ ... -06506.php

[6643]

You are correct; the 120 and 140 panels were identical in 1946.

I'm thinking you need to find someone less anal. It's not a safety of flight issue.

[7950]

Slightly related question - I have the brass version of these and on my C120 panel I don't seem to have the thread length to enable me to bolt through the instrument panel and the kidney shaped cover panel and still get some thread showing after the nut. I notice that the ones referred to here are the steel bolt version rather than brass. Quite a bit cheaper but are they longer / larger ?

[6643]

What nuts are you using? Is your panel original, or maybe thicker?

Lord M7504 (Aircraft Spruce) has a stud length of 3/8". Also, J6984-8 from (Univair), which has brass hardware. If your compass is in the panel, you might want to go with brass hardware, including the nuts and lock washers.

Lord has a whole series of J6984-X mounts. Maybe give them a call and see if one crosses to A301.

[7677]

I believe the A301 refers to the nylon capped nuts that hold the outer panel on. The part number for the shock mounts is: 10-14700. I know as I just had to replace mine. I purchased them from Spencer Aircraft in Washington. They are brass. I ordered the nuts separately.

Ken Hamilton
OR78
N77464

[7633]

An excerpt from the drawing detailing the effectivity and cross references.

8B14DFD4-B064-416A-8574-F2676EB6AEB0.jpeg (174.87 KiB) Viewed 8708 times

Jeff

[7950]

The design of the mount is the correct one but looking at the Cessna diagram in the parts book the nut is a standard UNC AN340-8 with a lock washer where as I was using a standard brass nyloc that is quite a bit taller I think and therefore takes more thread.

[VIP227]

I've been researching on this topic for a week, now. Obviously this is a very hot topic because I came across other type clubs where this has been discussed, too.
First, those who are looking for these A301 instrument shock mounts can find them at
https://cessnadirect.com/product-search ... query=A301

I had old instrument shock mounts in my 140 so I thought with all these fancy instruments I have I could afford new shock mounts, at least. I bought these round instrument panel shock mounts P/N 10-06506 from Aircraft Spruce (page 574 in their catalog) because they appeared to be identical to those A301 mounts. I installed them and when I came back after a couple of months abroad I saw that two of the four had come apart.
The problem is that these may be a (cheaper) replacement for Lord J6984-1, -8 and Cessna 0411059-1 - BUT - none of these are identical to A301. The disc to which the rubber body is molded has less than half the area of these discs on a A301 so they can carry only a fraction of that load. DO NOT USE THEM!
These Instrument Panel Shock Mounts from Univair (page 11 in their catalog), that one of you mentioned, are J6984-8 and these are not as big as A301, either - so also: DO NOT USE THEM!

I would like even sturdier ones than these A301 and I've found other people with the same problem in other type forums. My instrument panel is heavier than it was in 1946 because the instruments I have are much better than what was installed then. I bought my 140 in 1975 because I wanted a nice classic airplane with which I could build flying time (and that included instrument time) and have a lot of fun. The fact that I still have this airplane says it all.

The other day I had a correspondence with a very friendly lady at Lord but the only thing they have in that range was a not aviation approved shock mount with slightly larger dimensions but a 1/4-20 UNC-2A thread that would make it necessary to enlarge the holes in my panel.

So far I am still trying to find a good solution. So if someone has a good idea I'd love to hear (read) from you.