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Broken bolt stuck in prop hub

A

Andrew511

Active member
I have a 2 blade WW prop Held on by a 4 bolt hub. All bolts had nuts on the back and it’s a smooth bore bolt hole. 3 bolts loosened up and came out no problem. One bolt would not budge I was able to get the nut off the back no problem but ended up snapped the bolt head off flush with the hub. Even with the bolt head and other 3 bolts out the hub is fuzed solid to this bolt and won’t allow me to take the front plate ooff the hub. Any suggestions? I imagine drilling it out is no easy task
 
Use a punch. You say the nut is off and smooth bore hole, mix power steering fluid and acetone 50/50 and use it as a penetrating oil. Had hub bolt on last boat same deal but corrosion held the bolt Tight soaked it for over night hit it with air hammer and pushed it out from the backside.
 
PB Blaster and a little heat. Propane torch so not to cook the carbon. The heat will suck in the Blaster as it cools. Take a brass drift and a hammer and try to drive it through til it passes the split. When going back together use some kind of anti-seize.
 
Good air hammer is better than drift if you have one. Many little short hard hit jars a lot of things loose. Would soak it as stated earlier.
 
I agree on the air hammer. Don't like mushrooming the shank any more than necessary so it doesn't swell in the bore, hence the brass.
 
hdsadey said:
I agree on the air hammer. Don't like mushrooming the shank any more than necessary so it doesn't swell in the bore, hence the brass.
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So does the air hammer punch also need to be brass? And do I heat it then put the PB blast on it when it’s hot?
 
Don't believe they make them in brass. If your gonna use an air hammer just be gentle. If you go at it too hard you might end up swelling the shank and make more work for yourself. Heat it a little and spray, it will draw the Blaster in. WD40 works too, Liquid Wrench, anything that is designed to bust up corrosion.
 
hdsadey said:
Don't believe they make them in brass. If your gonna use an air hammer just be gentle. If you go at it too hard you might end up swelling the shank and make more work for yourself. Heat it a little and spray, it will draw the Blaster in. WD40 works too, Liquid Wrench, anything that is designed to bust up corrosion.
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I heated, then PB blasted and drilled a pilot hole for the punch to sit in and not bounce around (I used a air hammer) and this thing did not budge even a little. It was a pretty strong snap on airhammer too. I did ding up one small spot on the outside of the bolt but it didn’t move enough to even catch on it. This thing is STUCK
 
Andrew511 said:
I heated, then PB blasted and drilled a pilot hole for the punch to sit in and not bounce around (I used a air hammer) and this thing did not budge even a little. It was a pretty strong snap on airhammer too. I did ding up one small spot on the outside of the bolt but it didn’t move enough to even catch on it. This thing is STUCK
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Andrew,
I been there for sure, when you said a WW hub all that came to my mind was the 4 days I spent getting the old flat head hub off my motor last year to change the oil seal. It took me a whole case of beer and half a bottle of Whisky just to drill out the 6x flat heads. Then another 2 days of Acetylene rose bud and sledgehammer to get the hub off my crank.

But don't you have this hub off the motor? Do you know anyone with a hydraulic press? I honestly can't think of a shop tool beyond the basics that is more useful than a press. On my last offshore boat I had both outboards hanging off my overhead, laying sideways in the press just to get the trim systems apart. One of them went to 35 tons before it popped. I could not believe that the pin moved and did not crack the casting, but all was good.

Give the damn thing hell with a press, it is way easier on things than hammering on it if you don't have too, what do you have to loose at this point, at worst it's time for a new hub!
 
On my last offshore boat I had both outboards hanging off my overhead, laying sideways in the press just to get the trim systems apart.

This must have been fun to watch. And I agree, this would be a better way to remove it. Any good machine shop or most automotive repair place would have one.
 
Slidin Gator said:
Andrew511 said:
I heated, then PB blasted and drilled a pilot hole for the punch to sit in and not bounce around (I used a air hammer) and this thing did not budge even a little. It was a pretty strong snap on airhammer too. I did ding up one small spot on the outside of the bolt but it didn’t move enough to even catch on it. This thing is STUCK
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Andrew,


Give the damn thing hell with a press, it is way easier on things than hammering on it if you don't have too, what do you have to loose at this point, at worst it's time for a new hub!
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This hub is still attached to the engine I don’t see how I could remove it without getting this bolt off. I’ll attach a pic Incase I’m missing something
 
Some times drilling the center relieves the pressure of the bolt being lock into hole. Not talking drilling completely out just a center hole. Now looking at the picture looks like a little damage has been done by the bolts as in the aluminum looks slightly crushed in the 3 other holes. When you do get this off check the hole sizes and use all new hardware and make sure you use good thick quality washers
 
Andrew511 said:
This hub is still attached to the engine I don’t see how I could remove it without getting this bolt off. I’ll attach a pic Incase I’m missing something
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No, I was missing the "still on the engine" part, brain fart. I agree with Ted, get some good hardened bits and start drilling. You won't get on center, but need to keep the drill straight. Just keep increasing the drill size until just about to break into the aluminum. Once you get a weak point made it will loosen up some and should hammer out.

You still have the hub to crank bolts to deal with.
 
Also aluminum expands twice the rate of steel. Do the drill heat and penetrating oil then after it all cooled heat the outside of prop adp and see it comes off.
 
Andrew, aren't you getting a new motor, so perhaps beating on the crank may not be such a big deal.

With the picture staring at me for a bit I got to thinking. With all 3 of the other bolts out but the blades still in, the hub is probably cocked on the remaining broken bolt. You might try re-installing the other 3 bolts and giving them a good tightening with an impact while heating around the broken bolt and beating the hell out of it with a sledgehammer and a long punch. Snugging up those other bolts will move it around some and might break the log jam.

Careful on the heat though, I'm pretty sure the hub is made from heat treated aluminum. A rosebud will anneal the aluminum, cutting strength to 1/3rd and you don't want to get the blades too hot.
 
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