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Replacing Force One seal?

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Pops

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Many years ago I called Steve at Great Plains and was going to order the prop hub seal for the shunk-on prop hub. Steve told me to just go to the local NAPA store and buy a rear wheel seal for the VW Bus. I did and at the time is was a little over $7.
 
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Turd Ferguson

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The inner seal is a TRW (CR)19834, 2"x 2.75"x .25". The outer seal is a TRW (CR)19832, 2"x 2.75"x .3125".
I'm sure the size of Force One hub was dictated by standard off-the-shelf seals and bearing sizes. That would be much easier than having those items produced in a custom size.

wrt to the prop bolt hub bolt, I would go with the higher number, 80 ft/lbs. although it may be blasphemous to torque a metric bolt to english values......
 

Vigilant1

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Great Plains info on the Force One prop hub is scattered and incomplete. This post is to provide and consolidate reference material.
Marc, thanks for the info. My Force One is leaking a little bit, and this might be very handy. I'm lazy enough that I'd probably just keep wiping it up and adding oil, but I think I may have a little too much play in the crankshaft now, and that might force the issue.
Mark (with a "k" 😉)
 

akwrencher

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Just set your wrench to 108.47 nm and all will be well😉
I'm sure the size of Force One hub was dictated by standard off-the-shelf seals and bearing sizes. That would be much easier than having those items produced in a custom size.

wrt to the prop bolt hub bolt, I would go with the higher number, 80 ft/lbs. although it may be blasphemous to torque a metric bolt to english values......
 

Marc W

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I finished assembling it today and took it up for a while. It is still leaking! Nowhere near as bad as it was but it did leak. I don't know what to make of it. Maybe it is leaking around the outside of the bearing or between the case halves. Hard to tell when there is oil everywhere. I will fly it again in a couple days and see what happens.
 

Hot Wings

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Try some UV dye in the oil and then inspect under a black light in a dark area after a short ground run.

I've never tried the cell phone trick. I have a 'normal' black light.

Was the prop flange without wear groves from the old seal?
 

Marc W

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There were light wear grooves. I don't think they were deep enough to cause a problem. But, there was some raggedy machine work done when the hub was made. There are some ugly lathe tool marks that didn't clean up when the bearing and sealing surface was ground. The tool marks are probably why it always weeped a few drops of oil every flight. I actually thought about taking it to one of our EAA members who does precision grinding to have it cleaned up in the seal area. If I had the hub ground I might have to find a seal with a smaller ID depending on what size it ended up at. I can live with it weeping a few drops so I just put it back together.

I may have screwed up when I put the seals in. I didn't put any sealer in the housing or on the seal when I installed it. The seals have a sealer on them so I didn't add anything. Maybe I should have. There was residue from some kind of sealer in the housing when I took the old seals out. So it could be leaking around the OD of the seal.

I will fly it again tomorrow and see what it does.
 

Mac Hodges

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Marc W-Oil can leak between the inside of the Force One hub and the crankshaft. Remove bolt on end of crank and coat washer and bolt with oil resistant silicone and retorque.
 
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