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Elevator rod-end jam nut torque

AntiGravity

AntiGravity

Well Known Member
As a follow on from my other elevator question: should the jam nuts on the rod-ends be torqued? If so, how do you do it? (and how much for one of those nuts). I can barely get an open ended spanner in there to tighten 'em up...
 
osxuser said:
Tight... they should be tight and torque-sealed.
Click to expand...


I'm glad I'm not the one who said that :D

Seriously, you just can't torque every single bolt. For example, anyone who says he properly torqued the main gear bolts on an -8 is a liar :p
 
For this location, my EAA tech counselor recommended just "get it [the jam nut] tight" and then put some blue threadlocker on it. Really, where's the rod end going to go with or without the jam nut? I don't see how the rod end could possible unthread itself since it is essentially fixed in place by the elevator/hs hinge. Thus, the jam nut seems to be a little pointless even it it is customary to use one.
 
They're as tight as I can get them, but not torqued. By 'torque-sealed' do you man that enamel stuff, or whatever it is, that you put on to see if a bolt moves over time? Like marks on tyres to see if they're spinning on the rim? Cheers...
 
As far as I can tell, the jam nuts in this case aren't there to prevent turning. They're there to preload the rod end threads slightly so that it doesn't vibrate in the nut plate. Over time, this would cause a loosening of the rod end resulting in wobble, even more vibration, and eventual failure of the threads.

Maybe someone has asked Vans about this and knows why they're there, but this is the only reason I can figure.
 
Tighten them just enough so that the inspector can't move them (right Mel?)!

I couldn't see any point to these either, but I like the anti-vibration explanation....

Paul
 
As a newbie to the list and just beginning electrical here goes ...
Isn't it possible to torque the aft end before the tube is in place (like on the work bench) then torque the front end with a crow's foot when the tube is in place?
My 2 cents worth
Jerry Grimmonpre'
 
They're torquable

I was able to torque mine(my notes say to 175 in/lb - specs for this thread say 160-190) using a Craftsmans 3/8" drive crows foot and a "wobble" extension. A "wobble" extension for those who don't know is like a regular square drive extension but the socket(male) end has a slight taper to enable the user to lean it a bit to clear any obstructions(like the edge of the access opening in the leading edge of the elevators). I figured by going to the center of the tolerance I would allow for any inaccuracies resulting from the very slight offset from the nut centerline. Having said all that I agree that "secured" would be tight enough. I mean, where the heck can it go?!
 
Yes, torque seal, inspectors tape, fingernail polish, whatever works to verifiy that they aren't moving. And the vibration explanation is correct. If the jam nut comes loose, the rod-ends will distroy their own threads from vibrating, I've seen it happen in a reletively small amount of time (between annuals on aircraft that fly <100hrs/year).
 
Hawkeye7A said:
I was able to torque mine(my notes say to 175 in/lb - specs for this thread say 160-190) using a Craftsmans 3/8" drive crows foot and a "wobble" extension.
Click to expand...
Longshot, but anyone know of a place I can buy a crow's foot online for shipping to NZ? Haven't found anywhere so far. I'll check my local hardware stores, but I look in the tools section a lot; I'm pretty well known since I started the plane :D. I havent' seen a crows foot or anything like it there...
 
One place to try would be Ebay - there are quite a few for sale there.

Does craftsman (sears.com) ship to NZ?

Thomas
-8 wings
 
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