Prop Questions

[13jeff13]

SO not to take away from others thread about prop issues,, I would like to remove my prop tube hose, and need direction with this en-devour as well. I cleaned up the prop and attaching Nut, and have yet to try to remove it,, NOT SURE if it is reverse thread or not,, and letting it soak with some CLR to remove the build up around the threads.

Is it better to remove the prop and bring it out thru the cabin,, OR, remove the coupler and the "packing nut" and take it out thru the outside? Not sure what the packing nut aperture's proper name is... the Cutless Bearing isn't loose,, but looks original,, and a little dry rotted. SAME with the Hose that attaches to the "Packing Nut" and the Prop Tube,,, doesn't look terrible,, but Original, and dry rot looking,, the Hose clamps where almost rusted off,, just broke off,, nothing left to unscrew. But welded on by time.

Lastly, ,can you guys decipher the Numbers on the Prop,, do they have meaning,, or just casting numbers?

As Always,, Much appreciative of all Info,, Help.

Jeff

[Marian Claire]

Look forward to the posts on this as I have never removed a prop. I believe the #s mean you have a 11" diameter 7" pitch right hand, spins clockwise when viewed from astern, bored for a 7/8" shaft. Dan S/V Marian Claire
Edit: A 11x7 is on the small end of the recommended two blade props for direct drive A-4. Assuming direct drive by the 3 bolt coupling.

[sastanley]

Ya hoo! Go for it Jeff. You don't want to discover prop shaft or stuffing box problems after launch. Now is the time to pull all that apart and make it right. A cutless bearing is about $40. A new stuffing box is about $75. You may be able to get away with new "stuffing box hose" & some goretex packing (back in the old days they simply used exhaust rated hose, the newer stuff is much more substantial and I recommend it.)

Those nuts on the stuffing box are regular thread. The usual procedure is for them to be jammed together so they don't move...get the skinny nut loose from the fat nut (where the packing is hidden) and then the fat nut should spin off. They should spin off with the wrench handle headed in the stbd direction.


First step: get the couplers apart at the back end of the engine
step two: get shaft half of the coupler removed from the shaft

[13jeff13]

It all seems so clear when someone else says what you only suspect. I seen the 11 x 7 on the back side and didn't correlate the 11RH7 to mean what you stated.. Duh moment.. ,, I then too assume that since the Grampian is a 1973 model, ,the 1 73 is when it was cast,, in Grand Rapids, Michigan,, by perhaps a company Sailor? or perhaps just meant to be for a sailor....


Still looking forward to instructions on how to proceed.

oh yeah,, I already removed the stainless cotter pin from the nut area at the prop.

[sastanley]

Ooops...Jeff, I think you are right...maybe an 11" diameter by 7" pitch prop..ignore my other post..I didn't look closely enough at the extra pictures.

Michigan Wheel made a "sailor" prop I think, built for sailboats. those numbers don't really mean anything to us...that's what the prop shop guys are for.

Now, you gotta figure out a way to hold the shaft still so you can break the prop nut loose.

[13jeff13]

I see. So leave the prop on and remove the stuffing box and coupler. I read somewhere that the coupler shouldnt be reused? Is that good info?

[ILikeRust]

Originally Posted by 13jeff13

I read somewhere that the coupler shouldnt be reused? Is that good info?

IMHO, yes, that is good info. Other might disagree. If I were to do it again, I might go with a split coupler. In any case, I would recommend that you get a new coupler and have it fitted and faced.

Here are a few sites that will be helpful to you:

http://www.pbase.com/mainecruising/stuffing_box

http://www.pbase.com/mainecruising/replacing_a_cutlass

http://www.pbase.com/mainecruising/fitting_a_prop

[13jeff13]

I got the Hose cut,, it was very dry rotted, and came apart pretty easy. Now the rest of the components are soaking in Kroil til Thursday. I hope they come apart as easy.

[13jeff13]

Got a chance to wipe down the engine compartment,, Them wires look so much better in them Black Wire Holder Tubes.

[Laker]

I was going to post the stuffing box essay , but rust beat me to it. Study it closely , great stuff.

Keep up the good work ; when you are finished you will really know your boat.

CJK

[Loki9]

If it was me, I'd pull the prop off the shaft and then remove the shaft from inside, leaving the coupler on the shaft. You'll save yourself some aggravation as the coupler does not come off easily and if you do get it off, you may need to replace it.

[hanleyclifford]

From the point where you're now at it would be just as simple to pull the prop and then withdraw the shaft and coupler forward. Clean up and then decide about the coupler: I reuse them routinely.

[msmith10]

If you do pull the shaft forward and leave the coupler on, take it to a machine shop and make sure the face of the coupler is perpendicular to the shaft. Otherwise no amount of alignment will fix the resulting shaft wobble. I speak from personal experience.
You need to do this if you replace the coupler, also.

[sastanley]

Originally Posted by msmith10

If you do pull the shaft forward and leave the coupler on, take it to a machine shop and make sure the face of the coupler is perpendicular to the shaft. Otherwise no amount of alignment will fix the resulting shaft wobble. I speak from personal experience.
You need to do this if you replace the coupler, also.

+1

Take the easiest route to remove the paritial assembly from the boat, and let the pros deal with removing the coupler. I damaged mine forcing it off & had to replace it.

once removed, take both coupler pieces & the shaft to a prop or machine shop and let them do the fit/facing/aligning, so everything will be true when you re-assemble. If you plan to re-use the prop, take that in too and let them balance that as well.

[jhwelch]

Once a coupler has been fitted/faced does it have to undergo this process if you replace the shaft? It seems to me that all shafts would fit into the coupler the same way. Last summer I paid for fit/facing when I replaced my shaft and kind of wondered if I was being "shafted".

-Jonathan

[ILikeRust]

Yes, the coupler has to be a reasonably precise interference fit - a snug press fit. Which means it should be reamed with reasonable precision on a lathe, and then the coupler faced on the lathe to assure the face is perpendicular.

[13jeff13]

Originally Posted by ILikeRust

Yes, the coupler has to be a reasonably precise interference fit - a snug press fit. Which means it should be reamed with reasonable precision on a lathe, and then the coupler faced on the lathe to assure the face is perpendicular.

Does the same apply to the split coupler?


Jeff

[13jeff13]

Originally Posted by hanleyclifford

From the point where you're now at it would be just as simple to pull the prop and then withdraw the shaft and coupler forward. Clean up and then decide about the coupler: I reuse them routinely.

Yes Hanley, I Like Your suggestion. It will be much easier to work on the coupler and stuffing box on my bench, ,than in the belly of the boat.




Jeff

[13jeff13]

Originally Posted by Laker

I was going to post the stuffing box essay , but rust beat me to it. Study it closely , great stuff.

Keep up the good work ; when you are finished you will really know your boat.

CJK

Thanks,, You are right,, ,it is such a learning experience, and to know her top to bottom will make me a much more confidant sailor.

This site and the Guys here are such a wealth of knowledge,, a group I am proud to be a part of.

Jeff

[13jeff13]

Originally Posted by Loki9

If it was me, I'd pull the prop off the shaft and then remove the shaft from inside, leaving the coupler on the shaft. You'll save yourself some aggravation as the coupler does not come off easily and if you do get it off, you may need to replace it.

Yep Jeff I agree,, Now the Nut that holds the Prop on, I haven't looked a great deal at it, and I am sure I can figure it out, But are they normally reversed threaded, or other. Also the Prop itself,,, is it being pressed onto a taper,, and I believe a Key as well?

I will read thru Bill's "I LIKE RUST" post/link as well, I gave them a glance on my Android today, ,Had to do a double at work, gives things time to soak, haha.



Jeff

[13jeff13]

Originally Posted by sastanley

+1

Take the easiest route to remove the paritial assembly from the boat, and let the pros deal with removing the coupler. I damaged mine forcing it off & had to replace it.

once removed, take both coupler pieces & the shaft to a prop or machine shop and let them do the fit/facing/aligning, so everything will be true when you re-assemble. If you plan to re-use the prop, take that in too and let them balance that as well.

Great thoughts Shawn, ,and from everyone. It was your Prop Tube Rebuild, ,that was in the back of my mind, every since I read it, that really encouraged me to give mine a good looking over. Glad I did.

Thanks


Jeff

[sastanley]

Originally Posted by 13jeff13

Yep Jeff I agree,, Now the Nut that holds the Prop on, I haven't looked a great deal at it, and I am sure I can figure it out, But are they normally reversed threaded, or other. Also the Prop itself,,, is it being pressed onto a taper,, and I believe a Key as well?

I will read thru Bill's "I LIKE RUST" post/link as well, I gave them a glance on my Android today, ,Had to do a double at work, gives things time to soak, haha.



Jeff

Jeff,
Yes, the prop is on a taper with a key..It is a process of tightening a puller onto it and slowly continuing to tighten and tighten, and POW!, suddenly it pops loose. The coupler also has a key, but as Bill noted, it is a 'snug' press fit with a dimple in the shaft and a lockscrew. Mine was so tight, I had to press the coupler off the shaft one turn of the wrench at a time.

I don't think the stuffing box nuts are reverse threaded. I have a note written in Sharpie in the little access hatch on my boat which remindes me which way is "loose" on the stuffing box nuts. I am pretty sure they are normal right-handed threads.

[Loki9]

Originally Posted by 13jeff13

Yep Jeff I agree,, Now the Nut that holds the Prop on, I haven't looked a great deal at it, and I am sure I can figure it out, But are they normally reversed threaded, or other. Also the Prop itself,,, is it being pressed onto a taper,, and I believe a Key as well?

Jeff

It should be a normal right-hand nut holding the prop (plus a taper and a key). After removing the nut, you will need a puller to get the prop off. My boatyard had one I was able to borrow. Tighten the puller, and then give the prop a few whacks with a hammer to knock it loose.

-Jeff

[Laker]

Props have extremely good memory regarding the bond to the shaft - a good case for heat application?

[hanleyclifford]

The "key", if you will, to stressless prop and shaft management is a totally anal approach to cleaning the parts beginning with the keyway which should have it's inside corners squared and inspected with a magnifying glass. The key itself must be cleaned and sanded lightly on a flat surface using something like 400 wetordry. The tapered shaft hole on the prop itself is most challenging but should be cleaned until the key can be pushed thru by hand. At assembly all parts should be lightly oiled and fitted together by hand and seated before any mechanical pressure is applied. This will ensure solid and concentric assembly and most importantly, easy removal. Of course, this does not help now unless the PO did as above. I do not recommend the use of heat in this instance. Also, pullers are cheap and IMO should be part of the boat tool kit. FWIW