Small Continental Prop Hub Removal

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Tiger Tim

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So I know how to get the hub off a small Continental with the tapered shaft, I just don’t like doing it. The nut being captive and becoming its own puller always feels like something wants to break. Are there any tricks to getting the taper to let go easier?

I’m in no rush, just thinking replacing a main seal on an A40 is in my future and want to file away any knowledge and advice. Thanks!
 

TFF

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I know there is a video on YouTube of someone doing it. Is it like the way you do it?
 

Victor Bravo

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There is a simple tool you make up for this. It's a piece of steel tube that is hacksaw cut to leave a little tongue sticking out, and you press this tongue into the gap in the snap ring that sits in the tapered prop adapter.

The tongue prevents the snap ring from compressing and jumping out of the groove in the adaptor. So with the snap ring unable to jump out, loosening the big barrel nut pulls on the snap ring, and all the force cannot do anything other than pull the prop adapter off without "snapping" the ring out of the groove.

A very very light film of that really high quality grease, the one that's mustard yellow colored (can't remember the name, but I have a can in my shop!). is well worth it.
 
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Turd Ferguson

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Are there any tricks to getting the taper to let go easier?
Yup. The "trick" is a strategically placed light tap with a lead or aluminum hammer. This article from vintage a/c magazine shows where the tap is used. This same technique is widely used on machine tools where 'locking' tapers are commonplace. A light tap unseats the taper for removal.

 

Dan Thomas

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It takes a LOT of torque on that nut to pop it loose.

And I sure wouldn't use any grease on the taper. The prop is the flywheel, and if there isn't a firm bond between the hub and crankshaft it will start slipping and eventually tear the key out and wreck everything.

Here's what the A-65 overhaul manual says about that nut:
1623776645708.png

It's on there tight. They don't want any slippage.

The Manual: http://my.kwic.com/~sinnamon/taylorcraft/A65 Manual.pdf
 

starrtit

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Re p/n 3745, tapered prop. flange nut torque. Nowhere have I ever seen it listed,and I have worked on a65's a few times in my life.
Is a photo stating the torque to be 200# available, I have always used 90 ft lbs.
 

Tiger Tim

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I always went snug then the next hole for the pin on an A65 hub. That has to be between a hundred and a billion pound feet since those holes are IIRC every 60° at best.
 

proppastie

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Re p/n 3745, tapered prop. flange nut torque. Nowhere have I ever seen it listed,and I have worked on a65's a few times in my life.
Is a photo stating the torque to be 200# available, I have always used 90 ft lbs.
See post 7
 

Dan Thomas

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I always went snug then the next hole for the pin on an A65 hub. That has to be between a hundred and a billion pound feet since those holes are IIRC every 60° at best.
I have one here somewhere, buried in a box, but it seems to me that there are maybe six holes in the nut and four or eight in the hub, which has a vernier effect on hole lineup. Set it to 200 ft-lb and see how close it is and adjust slightly as necessary.

Too little torque is not good. Any damage caused by slippage not only represents a safety issue, it represents a couple more scarce parts being scrapped. These engines haven't been built since the early 1960s.
 

Tiger Tim

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I have one here somewhere, buried in a box, but it seems to me that there are maybe six holes in the nut and four or eight in the hub, which has a vernier effect on hole lineup.
For some reason I thought there was only one hole on the hub and six on the nut (or vice versa) of the last one I did. In any case I definitely have 200lb•ft on it, plus whatever it took to get to the next hole.

I gotta make myself up a set of those tools though, and a nice little box to keep them in.
 

Dan Thomas

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For some reason I thought there was only one hole on the hub and six on the nut (or vice versa) of the last one I did. In any case I definitely have 200lb•ft on it, plus whatever it took to get to the next hole.

I gotta make myself up a set of those tools though, and a nice little box to keep them in.
Might drill more holes in the outer end of the hub for that locking screw. Here's a picture that seems to indicate that the hub has four holes and the nut five. Good vernier effect there.

1623981501346.png
 

proppastie

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I have heard some noise there were counterfeit hubs out there...champ owner at the airport had a hub crack at the key......it was a alleged NOS (new old stock) (still lots of WWII stuff out there ?) I think the mechanic might have over torqued it and just said that....
 

Dan Thomas

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I have heard some noise there were counterfeit hubs out there...champ owner at the airport had a hub crack at the key......it was a alleged NOS (new old stock) (still lots of WWII stuff out there ?) I think the mechanic might have over torqued it and just said that....
If the mechanic used grease or Never-Seize on the taper before putting the hub on, he would get a lot more stretch in that hub before reaching the specified torque value. The grease would let the hub ride farther up the taper and maybe split it.

The same thing applies to the wheel nuts on your car. If you use lube on them they'll end up pulling far harder on the studs when the torque is reached. Good way to break studs and wreck the wheels.
 

Dan Thomas

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A picture like that doesn't show the small distortions that are a sign of overstress. Partial shearing of the thread roots. The nut might also be harder than the crank, and the crank could suffer or even crack. Crankshafts don't take kindly to heavy shocks, like propstrikes. I had a crank fail in flight from a long-before propstrike.
 

dog

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A picture like that doesn't show the small distortions that are a sign of overstress. Partial shearing of the thread roots. The nut might also be harder than the crank, and the crank could suffer or even crack. Crankshafts don't take kindly to heavy shocks, like propstrikes. I had a crank fail in flight from a long-before propstrike.
First,I am useing the hub pictured as a custom fit cover for the taper on a complete engine that came with my project.
Second you are right about that hub bieng strested out ,there is a front spacer with that hub that has matching paint splaters,it tells a
story of egg shaped prop bolt holes and two
hammer marks on the rim.The inside of the prop hub where the snap ring rides when removing the hub has a raised wire edge from
repeated removal with a lot of force.
Third, there is a second motor that on very close inspection revealed a cracked and ever
so slightly bent web that is part of the front main bearing.
And then there are TWO other crank shafts,
and a BIG shelf of a-65 parts.
There is an engine builder in my province,not to
far away,and those cranks will get checked before use or sale.
 
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