Shaft coupler

I have to remove the shaft coupler to replace the hose on my stuffing box hose on my stuffing box the bolt that goes through the coupler andshaft have been ground off and mushroomed The question. is this bolt just threaded it on one end or is it a pin. I'm going to have to drill it out in order to get the coupling off. I can see about a half a thread on the opposite Side of the coupler

Doubt it's threaded. I would grind the mushrooming off one end and try driving it out with a punch and hammer. Both my boats have pinned shafts. One is a bolt with nut on the other end. The other is a pin with center punch marks around the holes keeping the pin in.

Ted

I drilled one and down past the thickness of the coupler and I'm punching it out with a. punch it's working

Remember, that ideally the coupler needs to be faced on a lathe AFTER it is on the shaft. That means that the coupler should be installed when the shaft is out of the boat. If it isn't faced you may have a tough time getting a meaningful alignment. Of course, putting the shaft in with the coupler on means pulling the engine.

TDunn said:

Remember, that ideally the coupler needs to be faced on a lathe AFTER it is on the shaft. That means that the coupler should be installed when the shaft is out of the boat. If it isn't faced you may have a tough time getting a meaningful alignment. Of course, putting the shaft in with the coupler on means pulling the engine.

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You can't be serious. If you mount a shaft in a coupler, face it on a lathe, disassemble it, then reassemble it in the boat, the repeatability will be perfect compared to everything else in the alignment.

Ted

O C Diver said:

You can't be serious. If you mount a shaft in a coupler, face it on a lathe, disassemble it, then reassemble it in the boat, the repeatability will be perfect compared to everything else in the alignment.

Ted

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I agree, not many boats or pieces of equipment you can do that with. Either that or 99% of the shaft alignments I've done or supervised were wrong.

The happy faces on an optilign wouldn't lie, would they?

TDunn said:

Remember, that ideally the coupler needs to be faced on a lathe AFTER it is on the shaft. That means that the coupler should be installed when the shaft is out of the boat. If it isn't faced you may have a tough time getting a meaningful alignment. Of course, putting the shaft in with the coupler on means pulling the engine.

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So basically what you're say is, nobody ever does this.

skipperdude said:

I drilled one and down past the thickness of the coupler and I'm punching it out with a. punch it's working

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Got it out

I realize I'm going to need a new coupler now because all the beating and heating I've done to this thing it can't possibly be true. What do you think of a two-part couple

We had the undersized but stock couplers on our boat replaced some ten years ago or so with larger, heavier split couplers. The shop said one advantage of split couplers is they help hold the shaft in alignment better tnan the old, shorter "lockbolt" style coupler.

It's important to safety wire the bolts in the split coupler, too, so they don't loosen up over time.

The coupling that Marin has posted work quite well. You could take your coupler and shaft to the machine shop, have them reassemble it, and face it on a lathe. Then they can spin it at an rpm equal to maximum in the boat and check the shaft and coupling to see how true they are. This is an area where I would defer the evaluation to someone who does this for a living, not an internet forum.

Ted

O C Diver said:

The coupling that Marin has posted work quite well. You could take your coupler and shaft to the machine shop, have them reassemble it, and face it on a lathe. Then they can spin it at an rpm equal to maximum in the boat and check the shaft and coupling to see how true they are. This is an area where I would defer the evaluation to someone who does this for a living, not an internet forum.

Ted

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I believe that is what I said above, which you dissed.

Last Fall when I pulled my shaft I took it to the machine shop and had them test it for true and reface the coupler. Standard procedure as far as I am concerned.

If you simply slide a new coupler on, make sure to use a good dial gauge to test the face for true orientation. Aligning an engine perfectly to a shaft face that is not perpendicular to the shaft means the engine is misaligned.

I think we were critical of the claim that the coupling must remain attached to the shaft during installation, not the quality of the fit.

I did say ideally. A test with a dial gauge is OK as long as you make adjustments to true the coupler as best you can (i.e., tunk it with a mallet and then check for true again - repeat as needed). It is still best to face the coupler after mounting it on the shaft.

TDunn said:

I believe that is what I said above, which you dissed.

Last Fall when I pulled my shaft I took it to the machine shop and had them test it for true and reface the coupler. Standard procedure as far as I am concerned.

If you simply slide a new coupler on, make sure to use a good dial gauge to test the face for true orientation. Aligning an engine perfectly to a shaft face that is not perpendicular to the shaft means the engine is misaligned.

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That might be what you meant but, to me at least, that's not how it read.

TDunn said:

I believe that is what I said above, which you dissed.

Last Fall when I pulled my shaft I took it to the machine shop and had them test it for true and reface the coupler. Standard procedure as far as I am concerned.

If you simply slide a new coupler on, make sure to use a good dial gauge to test the face for true orientation. Aligning an engine perfectly to a shaft face that is not perpendicular to the shaft means the engine is misaligned.

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There is a difference between the evaluation and the process. The process of reassembling an already matched and faced coupling and shaft once in the boat, is a common industry practice. The evaluation of whether or not to reuse a coupler should be based on a physical analysis by a professional who does this regularly, not anecdotal evidence posted on the Internet.

Ted

Thanks to all who contributed. Enjoyed this thread thoroughly
Al-Ketchikan

The split coupling is what I prefer to use. And yes, best to have it faced on a lathe while installed on the shaft. It will preserve it's runout after installing in the boat unless end of shaft is a mess.

If shaft is new, then it probably will be near zero TIR out of the box, but if shaft is new it's already at the machine shop, so why not take a skim cut or at least indicate it.

I HATE solid couplings. Splits and tapers are good.

With regards to our boat, we had one shaft pulled and straightened and the cutless bearing replaced. On the shop's recommendation when the shaft was replaced a new split coupler was installed instead of the original coupler. The coupler was installed after the shaft was installed obviously. I have no idea if the coupler was faced or if they just took it out of the box and put it on. There was no mention of facing anything. I would think that the coupler would be manufactured accurately enough not to need that but it's not my area of knowledge.

A couple of years later we had the other shaft replaced at the same time the cutless bearings were and a new split coupler installed in place of the original. Again, no mention of facing or line item charge for it on the bill.

In each case the engine was aligned with the shaft after it and the new coupler were installed and that was that.

Given the relative simplicity and relative crudeness of the whole driveline aft of the transmission I'd be interested to hear the shop's opinion of the necessity of facing a coupler before it's installed unless couplers are manufactured to very poor tolerances, which they don't appear to be.

Considering how poorly mounted and secured many engines are, I'm not sure how necessary it is to face a new couple either. But it's not I believe about whether the couplers face is true and square out of the box, it's whether is still is once it's on the shaft.

Split coupling deflects when it clamped to the shaft. How much depends on tolerance in the fit. More important to face a split than a taper. I have no problem fitting a taper with no skim as the fit is by nature self centering. Still best to at least check it, whole lot easier in the mech shop then troubleshooting wobble in the boat.

No need to face solid couplings as I throw those in the scrap bin.

Rebuilding my stuffing box this is my old hose I picked up some new hose. what do you think will this work?

Marin said:

We had the undersized but stock couplers on our boat replaced some ten years ago or so with larger, heavier split couplers. The shop said one advantage of split couplers is they help hold the shaft in alignment better tnan the old, shorter "lockbolt" style coupler.

It's important to safety wire the bolts in the split coupler, too, so they don't loosen up over time.

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Man put a skirt on that coupler and I would ask it to marry me, well at least Id ask it to cruise the caribbean with me.

skipperdude said:

Rebuilding my stuffing box View attachment 45024 this is my old hose I picked up some new hose. View attachment 45025what do you think will this work?

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They make a specific type of hose just for that application. If that hose in the picture meets those requirements then use it. If not consider getting the correct type of hose.

http://m.go2marine.com/gstore/go2marine/controller?productId=52033F

When realigning the engine to the shaft what are acceptable tolerances on a on a dial indicator

skipperdude said:

When realigning the engine to the shaft what are acceptable tolerances on a on a dial indicator

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Do you mean when you are target wiring or laser aligning the shaft to the engine? Or aligning the coupler faces to each other?