Frozen Prop on SX-M Duoprop, Seeking Advice

[Jason_SJC]

After owning the boat 4 months, I dinged up a prop and tried to remove it to take to our local prop shop. The rear prop was easy but the forward prop is frozen on. I used a 3-point puller and generated enormous force, but the hub and outer prop began to separate. The shop said they would replace the hub, but LORD HAVE MERCY I'm not sure how to get the prop off at all.

While abusing the prop shaft, gear lube oil began to leak from the lower unit. So I am prepared to drop that and reseal it. Does that mean I should now use heat to try to break the hub loose from the forward drive spline?





A second, stupider mishap is that I put a half inch socket drive in between the prop and the outdrive, which took a little chunk out. I'm planning to take the case to a guy around here who will build up new aluminum on there, and then I'll finish it back by hand.





Any procedural advice you can offer is appreciated. Thanks!

 

[Scott Danforth]

volvo recommends pulling the props and greasing the shaft often to prevent this vary issue. with only owning it for 4 months, it sounds like you may not have pulled the props when you got it.

I have had to cut props off because the hub was stuck to the shaft from lack of greasing. once the prop was cut from the hub, the hub sleeve is carfully cut with a die grinder and 2" razor wheels.

have you tried to use some kroil between the shaft and hub. then a dead-blow hammer to try to drive toward the drive, and the puller to work it back and forth. it will be tedious.

you will need to pull the shaft carrier to weld that up and re-seal. I think its 356A for the alloy.

 

[alldodge]

Maybe @Rick Stephens , @Bondo @muc @kenny nunez might have some ideas, but I'm thinking heat will be needed, and housing will also need. Disassembly because of heat, and inability to apply force removing the prop on the outer shaft only.

The heat will probably damage the seals

 

[Jason_SJC]

I'll try a dead blow hammer with an iron pipe against the hub, around the splined shaft, to break it loose. We've already been hitting it with penetrating oil frequently.

 

[Rick Stephens]

I think you can get some heat on the prop hub. Wrap the seal area with an aluminum heat shield made from a soft 16 gauge or thinner piece of aluminum. Then use a small oxy acetylene welding type tip to heat just the hub. The expansion will go a long ways towards loosening that press fit you have happening. You know you already have to replace the oil seal on the inner shaft, just want to avoid melting it and making more of a mess.

That chip in the housing is pretty much meaningless. Problem with welding it is making the inside threads too tight for future housing removal and installation.

 

[Jason_SJC]

Will heating up the outer prop body help it slide off the hub? I can't tell what that material is between the prop and the hub. Is it a phenolic resin or some hard rubber?

 

[Jason_SJC]

Another question - how hard can I beat on that hub before I destroy something important in the lower? The amazing force we were applying with the puller had me worried. A sledge hammer seems like you could do some real damage. At what point do I cut my losses and start cutting off the prop and hub?

 

[alldodge]

Have not messed with VP DP. My B3 has is solid with no hub. Yours is probably rubber, so when heating it may catch fire.

I would not use a sledge. Keep the heat on and a hose or extinguisher near by

 

[alldodge]

Edit: Have to take that back. The DP doesn't appear to have a center hub, its solid SS same as B3. The item inside the splined shaft is the inner prop shaft seal

The puller has to be pressing against the splined shaft and the prop. My thought is your puller is pressing against the center or outer prop shaft and the prop. If that is correct and I'm seeing it right then the puller is starting to pull the outer shaft out of the housing thru the retainer

 

[Rick Stephens]

IMHO the prop is less spendy than the lower gears, bearings and case. I would be hard pressed to hammer much on anything. Problem is especially bad in bearings and gears and it only needs a tiny surface distortion to wreck one of them. Can you give a better picture of the hub area on that propeller?

 

[Rick Stephens]

Also, you may be able to drill or cut holes in the round body of the prop to get puller hooks in solid. You will have to be very specific on what you push against though, hence my request for a little better picture of the hub. I have never worked on a DuoProp VP - I am no help on where to push.

 

[alldodge]

Suggest get a pipe which slides over the inner shaft down to the outer shaft

 

[Jason_SJC]

The prop and its hub are slipping apart as I've used the puller. I was pulling against the center splined shaft, which is the power output shaft of the other (rear) prop. It would be hard for me to find a pipe of the precise diameter to push on the outer splined shaft alone, but it may be possible. I bought some 2" iron nipple while I was in town just now so I'll see how that goes. But the center power shaft has a divot in its center that seems made for the purpose.

It's dark now, but I may add more pics tomorrow. In the mean time, here are some labels added to the one I already shared.

 

[Jason_SJC]

I suspect that's rubber between the two surfaces, because while you're using the puller it fights you like crazy and then when you relax the puller the prop goes back a half inch! It's crazy. It feels like the rubber is rolling out with the prop and then snaps it back. Only after you get to a really high force do you make any true progress. And by "high force" I mean putting my body weight onto the ratchet, probably 100 ft pounds or better. Even with Fluid Film on the puller shaft the entire thing was hot to the touch. Crazy.

 

[alldodge]

Put a torch in that area

 

[Scott Danforth]

Prop and hub are bonded with rubber.

Maybe heat the prop enough to break the bond and pull prop off hub

Then put puller on hub

 

[kenny nunez]

3Xs with AD & SD. Have some vice grip pliers handy to handle the propeller when it starts to move. I once heated a Mercruiser stainless prop and the rubber expanded causing it to shoot off by it self. After the prop comes off hopefully you will be able to peal the rubber off then probably have to chisel off the hub.

 

[Rick Stephens]

The divot in the center of the shaft is for the live center when the shaft was finished up on a lathe.

Measuring the diameter of that shaft would make it super easy to get a piece of pipe to fit over it. There are so many sizes it boggles the imagination. You will have a local steel supply, machine shop or welding shop that will have what you need cheap. This will keep you from pushing so hard on thin snap rings and aluminum bearing seats in your lower case.

 

[Bondo]

Ayuh,..... Welcome Aboard,...... Set up yer puller, with abit of tension on it, squirt the 'ell outa the exposed rubber with Quicksilver Power Tune, 'n hit yer puller, if that's rubber, it'll slide right off,......

After that, it's cut, 'n wack, to see how much of what you can save,.....

 

[Jason_SJC]

The divot in the center of the shaft is for the live center when the shaft was finished up on a lathe.

Measuring the diameter of that shaft would make it super easy to get a piece of pipe to fit over it. There are so many sizes it boggles the imagination. You will have a local steel supply, machine shop or welding shop that will have what you need cheap. This will keep you from pushing so hard on thin snap rings and aluminum bearing seats in your lower case.

Thanks. This sounds correct. I want to transmit the force through the actual shaft and not ancillaries of the other shaft.