170 elevator trim push rod

How to keep the Cessna 170 flying and airworthy.

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MT_Don
Posts: 26
Joined: Sat Sep 03, 2016 3:12 pm

170 elevator trim push rod

Post by MT_Don »

Greetings,
Can someone explain, or point me to a site whee I can find how to remove the elev trim push rod? C-170; don't know if it changed for later models. Mine is rusted as exposed, and needs some TLC. The aft end is a simple bolt and bracket. The fore end disappears into the elev.

Thanks, Don Missoula, MT
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c170b53
Posts: 2527
Joined: Mon Apr 22, 2002 8:01 pm

Re: 170 elevator trim push rod

Post by c170b53 »

Welcome Don, thanks for joining the club. Next year's convention is just around a few corners in Cody, hope you can make it. There's a few members in your area they may be of assistance until you come up to speed in the maintenance department. You do live in a beautiful place. I love flying and stopping in to your town and I hope cooler temps and rain get to you asap to quench the fires.
Do you have an Illustrated parts manual? You can find one on the web with a search for Cessna 170 IPC . Removing the rod, it's attached by two bolts ( AN 3's ) aft one is easy forward one attaches to the trim actuator. I use long 1/4" extensions and work down the leading and trailing edge of the elevator to get at them. A bit of tongue twisting involved.
Again thanks for the support.
Jim McIntosh..
1953 C170B S/N 25656
02 K1200RS
MT_Don
Posts: 26
Joined: Sat Sep 03, 2016 3:12 pm

Re: 170 elevator trim push rod

Post by MT_Don »

Thank Jim!
This is a great help! Got the manual now.

Missoula is a great place, sans all the smoke we have from over 13 fires around the area, about a 30 mi radius. We're blessed compared to what S Texas, and FL are facing. Rain, what damaged them, would really help us. Rather ironic, eh?

I am planning to attend Cody next year, along with the family. I went to OSH this year, my last visit was in 1998 with my Kitfox. Thanks, Don :)
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VernH
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Re: 170 elevator trim push rod

Post by VernH »

HI Don,
On my A model, I disconnected the push rod at the trim tab, removed the elevator hinge bolts and, with help, moved the elevator aft. The bolt and nut are then exposed so you can disconnect the forward end of the push rod.
Fly safe!

Vern
1950 C-170A N5453C sn 19487
Based in Pensacola, FL. 82J
MT_Don
Posts: 26
Joined: Sat Sep 03, 2016 3:12 pm

Re: 170 elevator trim push rod

Post by MT_Don »

Hi Vern,
If I get you, remove the bolt from the aft pushrod & bracket. remove the couple of elev bolts, then slide the elev aft, disconnect the forward end of the trim push rod, and remove. Right?
Hopefully Pensacola is safe from Irma! Don
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c170b53
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Re: 170 elevator trim push rod

Post by c170b53 »

I should have written work the extension down the leading edge of the elevator from either L/E end. You can get a small wrench in there to hold one side and crank from the ratchet with extensions
Jim McIntosh..
1953 C170B S/N 25656
02 K1200RS
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GAHorn
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Joined: Fri Apr 12, 2002 8:45 pm

Re: 170 elevator trim push rod

Post by GAHorn »

Hi, Don!
Sorry I didn't get back to you sooner... I've been out on a trip and missed your email which came thru the website. (We've had some problems with that matter...a direct-to-me email works better usually.)

I see the tribal-knowledge has got an answer to you. Great thing about the Forums. More heads are better than one anyway.
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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n2582d
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Joined: Mon Apr 29, 2002 4:58 am

Re: 170 elevator trim push rod

Post by n2582d »

Don,

Let me add my welcome to the Association!

If I could add two things - probably things your A&P will do anyway. First, replace the locknuts on that actuator rod with castle nuts. Here's what I wrote several years ago:
The 170 parts manual shows the push pull tube between the actuator and the trim tab attached using a standard AN365 nut. Later model Cessnas use MS24665-132 cotter pins with AN320-3 castle nuts on both ends of rod between the actuator and the tab. "Cessna: Wings for the World, Part II" says that Cessna made this change after they lost a C-340 prototype during flight test when this bolt came loose.
Referencing this discussion your A&P may also want to consider castle nuts when reattaching the elevator. This is what Barron Aviation, the C-195 experts, have to say on the subject:
Also of interest is any hardware “subject to rotational forces”. This includes pulley and flight control actuators as well as the flight controls themselves. FAR part 23 and AC43.13 publications address this issue. Granted the 190/195 series aircraft were produced prior to these writings, however, it is still a good practice to replace the original friction locking hardware with mechanical (cotter key) type locking hardware. At least replace this hardware when these areas are disassembled for maintenance.
Second, check that the six bearings associated with the elevator and trim carefully. Make sure they are not frozen. If the trim actuating rod was rusty I can almost bet that at least some of the bearings need to be replaced. Aircraft Spruce sells a bearing greaser that works well for these bearings.

I live in the foothills south of Yosemite. This is what has been flying overhead this week.
75450473-49EC-4B5C-8904-F39EC55895BB-7502-000018C297C45C57.jpeg
The picture is from the internet. (My iPhone picture of the belly of a B-747-400 3000' above isn't quite as good.) :| We've only been evacuated once this summer. Crossing our fingers ... the fire season isn't over yet.
Gary
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nippaero
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Re: 170 elevator trim push rod

Post by nippaero »

Welcome Don. I hear the smoke in Missoula is pretty bad. I was just up in Kooskia (Down Hwy 12) this past weekend with my 170. We have a place up the river. I barely made it home through the smoke. It was not fun! Good luck with the elevator.

Mike
1952 170B
N8180A s/n 25032
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GAHorn
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Re: 170 elevator trim push rod

Post by GAHorn »

I and John Pugliese will "second" Gary's remarks about elevator fasteners coming loose. If you search you'll find John's article two years ago (or thereabouts) in which, after giving some kids rides in a Young Eagles Day, John headed home and the yoke slapped back into his chest and he nearly lost the airplane.
Turns out the outboard elevator hinge bolt had lost it's nut and the bolt had slipped out of place jamming the elevator in an upward position. He's lucky he didn't lose the airplane and his life over it. (By using power he was able to descend to a nearby airport and change his shorts.)
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
MT_Don
Posts: 26
Joined: Sat Sep 03, 2016 3:12 pm

Re: 170 elevator trim push rod

Post by MT_Don »

Mike, Gary, George,
Thank you all for the welcome and GREAT tips! I did get the elev partly removed, giving me access to the bolt for the rod end. I have it out and cleaned, will chromate it Sat, then gray and reinstall :)

Kooskia is nice, I'll have to drop into that nice grass strip! Attached is a photo from my house, looking north. There are mountains there, just smokey since mid-July - really bad since Sun, like 1/4 mi!! 8O

Be well! MT Don
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Missoula looking north....mtns & city are there !!
Missoula looking north....mtns & city are there !!
MT_Don
Posts: 26
Joined: Sat Sep 03, 2016 3:12 pm

Re: 170 elevator trim push rod

Post by MT_Don »

Thanks all for the tips. Got the rod, terminal end bead blasted, chromated and painted! Now the underside of my elev looks worse in comparison! :?
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C170 elev pushrod.jpg
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c170b53
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Re: 170 elevator trim push rod

Post by c170b53 »

Earlier this summer (Oshkosh) there was a fire just west of Frenchtown, east of Mineral Co, I flew through. Met two RV's after in Coeur D'Alene who had flown above it. The smoke column topped out at 14000ft and they had videos to prove it.
Was just a tough summer with the widespread smoke and poor visibility , conditions which are still affecting us in this early fall.
Fixing things as you go rather than do the big overhaul might be a way to get the most flying you can out of your plane.
Jim McIntosh..
1953 C170B S/N 25656
02 K1200RS
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