Prop Wiggle C85-12F

[7392]

This entry is for JOHN COOPER.....
John, I have tried to reach you by e-mail but it keeps coming back as undelivered. You were going to share
info on the prop hub for my 85-12F. I am at a point where I can spend a little time on resolving my prop
wiggle situation. Any information that you can share will be appreciated.

Thank you, sir.

Larry Surratt
89011
8015
C-85-12F

[6643]

Sent you an email. Let me know if you don't get it.

[Chiefrussell]

“Wiggle” as in ? It’s just a perspective, but “wiggle” seems serious as all the airplanes I have owned for the past 50 years, I’ve considered such movement as serious enough to refrain from flying until my IA/A&P says it’s airworthy. I witnessed the results of an unauthorized propeller on a Mooney years ago, but the owner thought it was a good deal? A 6 inch piece of one end of the prop broke off resulting in 3 of 4 motor mounts breaking when this airplane was over the Mountains. He was fortunate to find a suitable runway to land on in the Northern Sierras. Upon investigation by the FAA, it was determined that this particular propeller wasn’t authorized for this particular engine and airplane. Tips of propellers operate at near the speed of sound so, don’t take any unnecessary risks is what I live by. Hopefully, you will soon learn the reason for your propeller “wiggle”.

[edidin]

It would be helpful to get an update on what kind of "wiggle" was observed. Haven't seen it in the thread. End play was discussed, but then the prop was apparently removed because... Were other measurements of the prop or crank then taken?

You are close enough that a look-see might be organized. But a better understanding of what exactly is perturbing you would be helpful!

[7392]

Update on prop wiggle.....I finally got the prop off after two weeks of grunting, cussing, and more grunting. Thanks for
the help from John Cooper. Examining the hub, I found cracks in three different places on the back side plate, thus the
source of the vibration I felt in my toes and finger tips.
Now I am searching for a prop hub for my C-85-12F. If any one of our members has one or know of someone who may
have one, I would appreciate a hint. I have tried almost all of the major part suppliers with no luck. If anyone can ease my pain, I would really appreciate the help.

Larry Surratt
89011
(26r) JACKSON COUNTY

[7392]

It looks like I've been wrong all along.....I was going by the original engine log book. What I actually need
is a hub for a C-85-12.
Any leads in the country will be appreciated.

Larry Surratt
89011

[6643]

Someone probably changed the crankshaft a long time back. I'm curious if there is any mention of it in the logs. (There should be...)

The fact is, they could take the data plate off and put it on another engine, and that engine becomes the first...

I would have someone inspect the taper of the crank for cracks before you spend any money on a new hub. You might even want to do a dye penetrant inspection.

The hub from any C75 or C85 with a tapered crank will work. I think one from any A-series will also work, but you should confirm that before laying out any cash.

[6597]

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