Piper shimmy damper stc

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Firstflight

Filing Flight Plan
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Jimbo
Can anyone give input regarding the stc to modify non-serviceable shimmy dampers on Piper Cherokee? Has anyone done this modification and what was the result? I have a kit on the shelf uninstalled.
 
Are you asking about the Lord elastomeric STC'd shimmy dampers? You haven't provided enough information about the reason for replacing the shimmy damper to provide feedback. My experience with the Lord on 172s has been good, but there are lots of other things that cause nose wheel shimmy that a new damper may not fix. These include nose wheel tire and wheel assembly balance, tire condition, and wear/looseness in torque links.
 
Stan Cooper said:
Are you asking about the Lord elastomeric STC'd shimmy dampers? You haven't provided enough information about the reason for replacing the shimmy damper to provide feedback. My experience with the Lord on 172s has been good, but there are lots of other things that cause nose wheel shimmy that a new damper may not fix. These include nose wheel tire and wheel assembly balance, tire condition, and wear/looseness in torque links.
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Stan Cooper. Thanks for asking. The STC I was asking about is exclusively for certain piper products, such as a Cherokee with shimmy dampers that cannot be rebuilt. Installation of the STC allows the unit to be serviced with hydraulic fluid. Just wondering who may have used that STC and if it seemed worthwhile.
 
What is the cost difference in removing the old one, modifying it and re-installing it including mechanic (and possibly 337 and IA fees?) vs buying a new damper which may or may not fix your shimmy problem?
 
Timbeck2 said:
What is the cost difference in removing the old one, modifying it and re-installing it including mechanic (and possibly 337 and IA fees?) vs buying a new damper which may or may not fix your shimmy problem?
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I have the STC and the kit. It's been on the shelf long enough for the price to double. The installation less paperwork takes less than an hour. The Lord replacement is over $1000 with tax and shipping. So I think replacement is 3 times as much.
 
If you already own it and I looked it up at $172 then it would be a no brainer to pay your mechanic to modify your existing one vs buying a new Lord damper. However and I've read on this and at least two other forums, the shimmy damper is pretty low on the list as to what is actually causing your shimmy. Having said that, you may as well modify yours and scratch that probable cause off the list. Good luck.
 
Timbeck2 said:
If you already own it and I looked it up at $172 then it would be a no brainer to pay your mechanic to modify your existing one vs buying a new Lord damper. However and I've read on this and at least two other forums, the shimmy damper is pretty low on the list as to what is actually causing your shimmy. Having said that, you may as well modify yours and scratch that probable cause off the list. Good luck.
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Timbeck2. Thanks. Other things have been checked. Some hardware replaced. No change. It's a "little" shimmy, only on landing, and seems to go away if I just tap the brakes. So I guess I'll just let my mechanic do his thing.
 
I hope it fixes it. Mine happened to be a combination of a very unbalanced wheel/tire and the $954 steering horn.
 
Firstflight said:
Timbeck2. Thanks. Other things have been checked. Some hardware replaced. No change. It's a "little" shimmy, only on landing, and seems to go away if I just tap the brakes. So I guess I'll just let my mechanic do his thing.
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Have you checked for slop in the scissors? Tapping the brakes would compress the nose strut, giving the scissors more leverage to do it's part of the job. I can't see where a shimmy dampener problem would be resolved by tapping the brakes.
 
MauleSkinner said:
Have you checked for slop in the scissors? Tapping the brakes would compress the nose strut, giving the scissors more leverage to do it's part of the job. I can't see where a shimmy dampener problem would be resolved by tapping the brakes.
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Guess I'll have to check it with nosewheel extended and check for slop. One just never knows. I've a couple of other things to check also.
 
Get the nose wheel off the ground, turn it by hand if able and see where the slop is?
 
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