Control Yoke Bushing

[ptporebski]

Hello Everyone,

I have a 1959 C-172 and am completing a partial panel upgrade. I have converted to a standard six-pack configuration with a Gizmo mount for the Garmin Aera on the floating panel. I measured and drew the panel and bulkhead on AutoCad, cut a couple of prototypes on a waterjet out of plexiglass (clear acrylic). This allowed me to see the interferences that I didn't get correct. Now, I have cut the panel out of aluminum. While doing all this (and more) I noted excessive "play" in the control yoke. Problem is the u-joint is worn - so I have ordered a replacement from McFarlane. But I also noted there is a bushing mounted in the panel that is worn. I found a part number 0513056-1 at the very reasonable price of $5.53 from CessnaParts.com. They have a minimum order of $25.00. So I guess I could order 5 of the buggers. However, ...

Wag-Aero also has a Teflon Ball STC Number SA666NW. It shows a Teflon Ball that mounts between the control yoke collars (p/n 0513146-12). However I only have a single collar that attaches to the front of the panel. Does anyone know anything about this STC? It appears that I would have to modify my aircraft to use it. The idea of using a nominal 1-inch thick Teflon bushing seems better than the skinny elastomer bushing originally designed. I am hoping someone in the brain trust knows something about the aforementioned STC. Thanks, and see you at S-N-F!

Pete P.
1959 C-172

[GAHorn]

You have a 172. So it took me a moment to figure out which parts catalog, which page, which figure, which item, etc...you were talking about per the PN you gave.
But what you are discussing ...the "collar" ...is the forward portion of the "socket" (my word) which holds that teflon "ball" in position. The Wag Aero Teflon balls are good. I recommend them over the Cessna part.

You will re-use the collar. The only part you will likely replace will be that teflon ball.

[blueldr]

If you guys keep talking about installing "Teflon Balls", some environmentalist is going to bust his ass to get "Teflons" on the "Endangered Species List" and then the FUZZ will be out looking for bootlegged teflon balls on C-170s. I'm not well familiarized with "Teflons", but I just assume that it only takes one (1) "Teflon" to provade for the complete compliment of parts required in a C-170. Considering that it is very likely that son or daughter if the C-170, the C-172, of which over 35,000
have been built over these many years, may also require the replacement of this part. Can you even begin to immagine how many neutered "Teflons" would be roaming through the population? I admittedly have a very limited education in biology, but i assume that these neutered "Teflons" were all males. This is going to terribly unbalance nature, and I would expect to see a serious problem among the remaining female "Teflons" Oh my god! Wouldn't it be great to be an un-neutered male "Teflon" under those circumstances?
Makes me wonder if Wag Aero realizes what they may have started.

[cmsusllc]

Gotta love 'em.
Scott

[n2582d]

Pete,
The IPC drawing which has the p/n for the socket you listed isn't very clear. Does your yoke socket look like either of the ones pictured below? The teflon ball is designed to fit between two retaining sockets on the C-170, one on either side of the stationary panel. These sockets are mounted with three screws. If your socket is like the C-175 style pictured with four bolts maybe you could mount a second one on the back side of the panel to capture the teflon ball. Might have to trim the length to give you full elevator travel. It goes without saying that your A&P would have to supervise and OK such a modification. Wag-Aero lists the teflon ball as a PMAed part--which means (in my book anyway) that it can replace the identical existing part without an STC. No mention of STC SA666NW in their catalog.

Early 172 yoke mount.jpg (14.86 KiB) Viewed 23876 times

C-175 yoke mount.jpg (21.63 KiB) Viewed 23876 times

[bagarre]

Good point blueldr
After the extensive trapping in the mid 70's, you don't see many Naugas in the wild anymore.

[N2255D]

I used the Wag Aero STC on my C140 and Installed them on the 170 when I got it in 96. Not hard to do. Just have to play with the washers (for spacers) to get the ball to float freely without slop in the retainers.

[blueldr]

bagarre,
Fortunately, Naugas are inedible or there would be even fewer of them left.

[bagarre]

blueldr, That would explain the taste.

On another note, what is the link to the STC kit on WagAero's site? I've looked around and even tried searching for a few terms but I can't find it.
I'll be opening all that up (again) shortly and would like to swap mine out too.

Cheers.

[Bruce Fenstermacher]

The link takes you to the FAA STC cover page which doesn't tell you anything other than the STC is for installing Delron bearings on control shafts on certain aircraft. Doesn't tell you how to do it which is typical.

Here is my two cents on this and other products Wag Aero sells but it also might apply to other retailers. There once not to long ago was a time when lots of Wag Aero parts were not approved but were installed, A: with no paperwork and no one carried or B: with the appropriate paperwork ie 337 and maybe even an apporval by the local FSDO. These are the times we look back on years ago when things were a bit looser and pilots, mechanics and even the Feds used a bit more common sense.

As things started getting tighter and parts were scrutinized Wag and others scrambled to identify approval for their parts. The quickest of course was an STC that existed and probably the next quickest was the STC process. But ultimately Wag and others wanted to get PMA authority to make the parts the same way they'd always been. This process took longer but it seems by each new catalog is bearing more and more fruit for Wag these days.

So today in some cases for some aircraft there may be two bases of approval for Wag (and others) parts. If Wag has a PMA for a part then it is a direct replacement for that part no more approval needed. If the part is not the same part as originally found on your aircraft but will work and is covered under an STC then you use the STC as the approval.

Concord batteries specially sealed batteries are in the same category. They once required individual approval. Then Concord got an STC form most of their batteries and airframes. Now Concord has a PMA for lots of the same batteries as direct replacements for the original, no further approval required.

[GAHorn]

The Concorde battery issue is also covered under the AC 23-27, Parts on airplanes built prior to Jan 1, 1980.
...also the Wag Aero bushings.

[bagarre]

The Concord battery is a life saver when it's 20 degrees out.

My comment on the link to the bushings was more to say, I can't find the bushings on Wag Aero's site at all. Not just the STC or documentation. I cant find the product so I can click to buy it It's a difficult site to navigate.

[n2582d]

My comment on the link to the bushings was more to say, I can't find the bushings on Wag Aero's site at all. Not just the STC or documentation. I cant find the product so I can click to buy it It's a difficult site to navigate.

Did you try clicking on the blue "Wag-Aero" link in my post above? It worked to order the part for me.

[bagarre]

Wow, you'd think I'd never used a computer before. I completely missed that link.
Thanks for pointing it out again.

[bagarre]

Somewhere, there was a great article about shimming the 'ball brackets' ( for lack of a better term ) so that they dont bind when tightened up.
It had photos and everything on how to do it...but I can't seem to find it anywhere.

Does anyone have the link?