Removing the Propeller Shaft Flange - H41AC

[dkinzer]

I'm in the planning stage preparing to replace the stern tube hose and re-pack the stuffing box on our 2007 H41AC. This will require unbolting the prop shaft flange from the gear box flange and then removing the prop shaft flange from the prop shaft. My assumption is that the hole in the flange into which the prop shaft fits is straight (rather than tapered as it is on the aft end). There isn't a lot of space to use a typical puller setup so I'm guessing that I'll have to make a plate to use to push the prop shaft out of the coupling.

Questions:
- is there a retaining bolt on the forward end of the prop shaft or is the flange held in place just by the two set screws?
- is the fit of the flange on the prop shaft a light interference fit or its is a close sliding fit? I'm trying to get a feel for how much force will be required to slide the flange off the shaft.
- I assume that the shaft is keyed and one of the set screws bears on the key while the other bears on the shaft. Is the shaft dimpled to receive the set screw? If it is not dimpled there it is possible that a burr will have been raised on the shaft making it difficult to remove.

I'd be interested in hearing from anyone that has done this or has seen it done.

 

[Sailgunner]

I just did it. You need to make yourself a puller. I had one made at a machine shop.

Have a shop take a plate of steel, one inch thick and about 4" square. Have them drill four holes to match you shaft flange holes. Get four bolts for the holes. Have the shop make one or two 1" dowels two different lengths. Use the dowels as spacers between your plate and the motor coupling. Tighten the bolts and slowly remove the coupling. After it moves some you may need to use the second dowel that is a different length.

I can provide pics of what I have if you need them.

 

[dkinzer]

I can provide pics of what I have if you need them.

Thanks, but your description is perfectly clear. I'll be able to make the pulling plate with materials I have on hand.

 

[jssailem]

I contemplated removing my shaft flange and possibly the shaft. I talked with a prop shop and was advised, you need to bring the shaft and the new flange to the shop to have them machined so that they fit. He also recommended a split flange replacement. If you have the shaft out it is time to make sure the shaft is straight. Also the time to replace the shaft log, cutlass bearing, and strut bearing if you have one.

 

[JoeWhite]

Before you have a puller fabricated, try removing the 2 set screws first. In my case, they sheered off and I had no choice but to cut the shaft and order a new one.

 

[Tally Ho]

I contemplated removing my shaft flange and possibly the shaft. I talked with a prop shop and was advised, you need to bring the shaft and the new flange to the shop to have them machined so that they fit. He also recommended a split flange replacement. If you have the shaft out it is time to make sure the shaft is straight. Also the time to replace the shaft log, cutlass bearing, and strut bearing if you have one.

Yes, “fit and face” is the proper term I believe. Ensures that the shaft and coupling are perfectly mated and have a “press fit”.

I did all of that when I found some cracks in my 30+ YO bronze shaft on my O’Day 322.

The next year, I upgraded to a Volvo dripless shaft seal…very happy with the whole set up.

Greg

 

[RoyS]

Mine have all been slip fit and without an end bolt. The shaft will not slip out, however, after several years in service. The set screws do have dimples to fit into on the shaft. Algonquin makes an inexpensive puller for this job. By all means buy one. Prepare yourself for a miserable time separating the coupling from the shaft. Typically you can barely access this area to work. When you are near the end of your patience and start looking for penetrating oil, hoping for a breakthrough, you might as well try magic spells for all the help penetrating oil will give you. Have faith, it can be pulled, just not easily. If all else fails, a Sawsall always works, so you have hope. Lastly, as Jssailem suggested, put it back together with a new split flange type coupling. The four coupling to motor flange fasteners may be metric BTW. Use elastic lock nuts as these often vibrate off and are seldom inspected. Good luck.

 

[jssailem]

elastic lock nuts

Do you mean Nylock lock nuts, Roy? plus lock washers?

 

[RoyS]

I suppose so, except no lock washers.

 

[artboas]

I'm in the planning stage preparing to replace the stern tube hose and re-pack the stuffing box on our 2007 H41AC. This will require unbolting the prop shaft flange from the gear box flange and then removing the prop shaft flange from the prop shaft. My assumption is that the hole in the flange into which the prop shaft fits is straight (rather than tapered as it is on the aft end). There isn't a lot of space to use a typical puller setup so I'm guessing that I'll have to make a plate to use to push the prop shaft out of the coupling.

Questions:
- is there a retaining bolt on the forward end of the prop shaft or is the flange held in place just by the two set screws?
- is the fit of the flange on the prop shaft a light interference fit or its is a close sliding fit? I'm trying to get a feel for how much force will be required to slide the flange off the shaft.
- I assume that the shaft is keyed and one of the set screws bears on the key while the other bears on the shaft. Is the shaft dimpled to receive the set screw? If it is not dimpled there it is possible that a burr will have been raised on the shaft making it difficult to remove.

I'd be interested in hearing from anyone that has done this or has seen it done.

Ok,
There’s as easy way to get a prop shaft off the flange
Just be very patient and careful
You need to remove the existing flange bolts
Then remove prop set screws
Spray your favourite flavour of “remover” into everything
Go watch a football game. Or 2.
Get some longer bolts & nuts (& washers ) for your flange coupling
Spray in one more round of “stuff”
Get out your heat gun
Get a socket wrench socket slightly smaller than the shaft
Fit it between the flange & transmission coupling in the shaft hole
Warm up the flange. Like lots
Then very slowly, and carefully start to tighten bolts. Go opposite sides
CAUTION!!!
The flange is a casting.
Do not go crazy with the wrench.
If you aren’t getting any movement, more heat & WD.
If you “gorilla” this, you’ll crack risk cracking the flange.
Everyone I know who’s tried this has been successful, but you must be patient .

 

[artboas]

Ok,
There’s as easy way to get a prop shaft off the flange
Just be very patient and careful
You need to remove the existing flange bolts
Then remove prop set screws
Spray your favourite flavour of “remover” into everything
Go watch a football game. Or 2.
Get some longer bolts & nuts (& washers ) for your flange coupling
Spray in one more round of “stuff”
Get out your heat gun
Get a socket wrench socket slightly smaller than the shaft
Fit it between the flange & transmission coupling in the shaft hole
Warm up the flange. Like lots
Then very slowly, and carefully start to tighten bolts. Go opposite sides
CAUTION!!!
The flange is a casting.
Do not go crazy with the wrench.
If you aren’t getting any movement, more heat & WD.
If you “gorilla” this, you’ll crack risk cracking the flange.
Everyone I know who’s tried this has been successful, but you must be patient .

One more thing, a very good practice is to put 2 threaded holes into keyway stock.
When you want to remove them, you wind in 2 Jack screws. They come out 100% clean, versus using vice grips and gnarling them up.

 

[Rich Stidger]

Ok,
There’s as easy way to get a prop shaft off the flange
<snip>
Get a socket wrench socket slightly smaller than the shaft
Fit it between the flange & transmission coupling in the shaft hole
Warm up the flange. Like lots
Then very slowly, and carefully start to tighten bolts. Go opposite sides
<snip>

I have heard of this technique many times before now., but have never yet needed to try it myself.
What I want to know, when you tighten the longer bolts between the shaft flange and the transmission flange, with the socket spacer, what keeps the transmission flange from coming off instead of the shaft flange?

 

[Ralph Johnstone]

What I want to know, when you tighten the longer bolts between the shaft flange and the transmission flange, with the socket spacer, what keeps the transmission flange from coming off instead of the shaft flange?

A fervent religious belief.
A few pennies in the poor box every week.

And for you non-believing heathens, make sure the big hex nut on the Xmission shaft is bloody tight .

 

[artboas]

A fervent religious belief.
A few pennies in the poor box every week.

And for you non-believing heathens, make sure the big hex nut on the Xmission shaft is bloody tight .

View attachment 212678

Rich
Thanks for this
But, the compression force is between the 2 flanges, as the shaft is free to move fore & aft.
Once again, do this carefully.

 

[Rich Stidger]

And for you non-believing heathens, make sure the big hex nut on the Xmission shaft is bloody tight .

OK, I guess I forgot/never realized that there was a nut on the transmission shaft securing the flange in place.
Thanks for the picture.
Me, a heathen? Nicest thing anyone has said to me all week......

 

[Sailgunner]

Interesting idea using the coupling on the transmission shaft but for $20 I rather have a 1" steel plate made and not risk putting that much pressure on the transmission coupling.

 

[artboas]

Interesting idea using the coupling on the transmission shaft but for $20 I rather have a 1" steel plate made and not risk putting that much pressure on the transmission coupling.

It’s not the transmission flange that I’m concerned with to be honest. The prop shaft flange is cast. So the stress on its perimeter is the same if you use a steel plate, or the other flange.
If you want to fab a steel plate, then I suggest you just tack weld a cheap socket to its face, and that way the force is evenly distributed on the shaft.

 

[Sailgunner]

It’s not the transmission flange that I’m concerned with to be honest. The prop shaft flange is cast. So the stress on its perimeter is the same if you use a steel plate, or the other as I flange.
If you want to fab a steel plate, then I suggest you just tack weld a cheap socket to its face, and that way the force is evenly distributed on the shaft.

You could be right but I think my prop shaft is forged steel. Also as I stated have some 1" dowels made to press on the shaft. Also as I said I did this and it worked great. I did forget to mention to buy Fine thread bolts. There is a tremndous amount of pressure to be applied.

 

[Ralph Johnstone]

......

You could be right but I think my prop shaft is forged steel.

Correct. A cast iron flange would be unusual.

My first try would be to use the shaft and Xmission coupling flanges just to see how much force is required. If it's too much, then proceed to a 1" plate.

 

[Rich Stidger]

Other questions- Is it possible to remove the shaft from the flange and then reassemble it to the same flange without sending the shaft and flange to a machine shop?
And what is the technique to press the shaft back into the flange?