panel shock mounts

[logsdon]

I just discovered that eight of the ten panel shock mounts in my 170B are broken. That might explain the knock I have heard and haven't been able to locate. I note that Aircraft Spruce has a shock mount listed in their catalogue but it doesn't match the Cessna part numer which is #0411059-1. Any ideas for a fix or supplier of the part?

[lowNslow]

The Aircraft Spruce ones look identical, but if you want the Cessna part numbered ones they a available at http://www.cessnaparts.com/parts.cfm for about twice the price ($9.44).

[n2582d]

How is it that you have 10 shock mounts? Both the early and later style panels only call for 6 on the standard panels (fig. 40-3 and 43-2)?

I ordered my shock mounts from Aircraft Spruce--they appear to be identical to the original. I have the early style 170B panel. I was curious why somebody would have drilled two 3/4" dia. holes in the top of the stationary panel. Then I happened to notice (natuarally only after already ordering six shock mounts) that the optional "IFR" panel shown in figure 76 calls for two more shock mounts (fig. 76-44). The two holes were drilled at the factory yet they didn't bother to attach the shock mount brackets (p/n 0511010-4, fig.70-40) behind these holes.

[Paul-WI]

I also just replaced mine as well from Aircraft Spruce - they worked great. No more dash vibration. It also helped to have the prop balanced.

Paul
N3458D

[blueldr]

The instrument panel shock mounts are available from Grainger Industrial Supply as "shock mounts" p/n 3CC01, $1.39 ea. Check their catalog.

[lowNslow]

BL, they raised the price on their "vibration isolators" to $1.83!!

The problem I see with these is that they appear to be made of steel rather than brass, which is non-magnetic.

[logsdon]

Thanks for all the info. I actually have nine shock mounts on my panel. All but two were broken. They have obviously been replaced since manufactured since some of the nuts were differnt sizes and there were no ground straps or washers on any of the mounts.

[Bruce Fenstermacher]

BL, they raised the price on their "vibration isolators" to $1.83!!

The problem I see with these is that they appear to be made of steel rather than brass, which is non-magnetic.

Resurrecting this thread to ask if anyone can definitely confirm that the original panel shock mounts were brass as Karl seems to indicate.

And can anyone confirm that the Cessna genuine $14.40 replacement is brass as well? Or are they cad plated steel? How about the replacements sold by Spruce which look to be cad plated steel and now cost $5.75. We know the Grainger model is steel because it says so and the now cost $1.16.

Also can someone confirm the dimensions we need.

[lowNslow]

Bruce, I guess I shouldn't assume that my mounts are original but they are brass with brass nuts, note that the parts manual calls for a AN340B8 (brass) nut for the shock mounts. Chief Aircraft sells the Lord LD J6984-8 which is the brass shock mount for $6. http://www.chiefaircraft.com/airsec/Air ... ounts.html

[Bruce Fenstermacher]

There you go Karl. Giving me the exact part number and supplier to get the brass versions taking away any reason to buy the cheap steel versions.

Thanks

[GAHorn]

Wag Aero sells the Cessna part number 0411059-1, which are replacements for Lord PN: J6984-1, and specifically states the Cessna PN are steel studs.
http://store.wagaero.com/product_info.p ... cts_id=211

Here's Spruce's link:
http://www.aircraftspruce.com/catalog/i ... ounts3.php

[Bruce Fenstermacher]

So the BIG question is has anyone had any problem with the Cessna steel mounts?

I was about to buy 6 of the official part number with brass studs for about $50 total for six and shipping but the BL effect is starting to draw me back towards the parts at Grainger for about $10.

[N171TD]

The panel in a 170B or 172 have six mounts across the top three along the bottom Total 9
Steel works fine but then I have a compass mounted mid windscreen. I really doubt the top panel compass would be a problem but that would be for you to determine.

[ronjenx]

So the BIG question is has anyone had any problem with the Cessna steel mounts?

How about this:

Cut a piece of cardboard the shape of your panel.
Stick a steel screw (about the same mass as the steel panel mounts) in each corresponding location.
Hold the cardboard in place, then pull it away. See if the magnetic compass moves.
Do this with the aircraft pointing in the 4 or 8 major compass directions.

That should tell you if the steel will be a factor.

[steveinman]

Funny thing! I just replaced mine when I was installing an Angle of Attack Indicator because most were broken. I had been feeling like I must be out of rig because I was needing to hold right rudder in cruise to keep the ball centered. Now she flies straight as an arrow with those new shock mounts and my panel leveled up.