Pulling a prop shaft

[brettportzer]

So, I have had a small noise at the cutlass bearing for a bit and as a result haven't been running the boat that much, waiting for the winter layup to address the issue.

Inspection last year led to having the props done and that actually made a nice overall improvement, but I still had a specific noise.

I wasn't totally sure what to expect when I took apart the coupling, but I knew I had a split coupling.

Turns out, I also have a pin in the shaft, and it is not tapered.

Is this weird?

It was pretty easy to get apart, that was good, but, it is not what I was expecting?

Here are some pics:

 

[Captain Ralph]

The end of the shaft looks rough in your picture.
Was the coupler loose on the shaft?
How does the thrust bearing feel on the clutch?
Has the coupler ever been faced to the shaft?
Any run-out on the shaft?

 

[brettportzer]

Yea, I have the pin. I was able to drive it out very easily.

I am pulling the shaft to have it checked, and to replace the cutlass bearings.

Coupler was not loose on the shaft, in that I put a socket between the two flanges, over the transmission output center bolt, and put the bolts back in the back the coupler off the shaft.

But, it didn't need to break loose, it just steadily pushed out.

Shaft was last pulled by prior owner in 2012, with bearings and stuff box replaced at that time.

Thrust bearing on gear I don't know anything about.

 

[brettportzer]

By the way, both shafts have this coupling arrangement, it doesn't seem like it was pinned as a band aid for one that was misbehaving.

 

[SEVEN]

I had a squeak in my running gear. I pulled the shaft at the coupler and replaced the strut bearings. Problem solved.

 

[brettportzer]

That is the plan!

 

[madhatter1]

I have to pull a shaft this winter. My coupling puts up a helluva fight. Tough with even the right tools but they finally relent. Did port side last winter. No sound like a 22 shot when it pops. More like a 38. Glad your were fairly easy.

 

[Captain Ralph]

By the way, both shafts have this coupling arrangement, it doesn't seem like it was pinned as a band aid for one that was misbehaving.

The pin is SOP. I was not questioning that.

 

[brettportzer]

The pin is SOP. I was not questioning that.

I was! I hadn’t heard of that, was expecting a tapered type situation…

 

[Captain Ralph]

I was! I hadn’t heard of that, was expecting a tapered type situation…

Keyed and tapered shafts may be cool but a PIA when servicing is needed, Sometimes (like a prop) they do not want to come apart.

I hope you marked the position of the shaft and coupler. As I asked before, was the coupler ever faced with the shaft? If it was, you may be 180° out on your reassembly.

 

[brettportzer]

Keyed and tapered shafts may be cool but a PIA when servicing is needed, Sometimes (like a prop) they do not want to come apart.

I hope you marked the position of the shaft and coupler. As I asked before, was the coupler ever faced with the shaft? If it was, you may be 180° out on your reassembly.

Not pictured it also has a key, so it should only go back on one way I am thinking.

 

[Captain Ralph]

Not pictured it also has a key, so it should only go back on one way I am thinking.

Keyed AND pined.
Super cool.
Your simple pin design helps keep the shaft stay in on hard backing. The pin should shear in the event of a collision.

I remember rubber, fluid, C/V couplers and many other strange ways to combine a shaft to a clutch.
Your design is one of the more reliable & safe couplers.
It is subject to abuse and wear.

Your first picture may be showing wear on the shaft end.
Again I ask, Run-out checks and shaft facing been preformed recently?

 

[brettportzer]

I don’t know what shaft facing refers to, I guess?

As far as I know, nothing has been DONE to the shafts since 2012.

I have cleaned up the exposed shaft on the outside of the boat, and last year I pulled the props for the first time and had them cleaned up.

This year I am going to have the shaft checked and replace the bearings.

Did not pull them last year because cursory examination (including checking the prop end of the shaft with a dial indicator) suggested try having the props done first.

 

[Cricket]

The coupling faces should be checked to make sure they're true (flat) so they mate with the output coupling perfectly.
Any decent machine or prop shop should be able to spin the coupling and then "true" it up if needed.
When we did our CAT repower both the output and shaft couplings were machined to match perfectly flat from Gregory Poole..

 

[Captain Ralph]

I don’t know what shaft facing refers to, I guess?

The shaft and coupler is assembled on a big asp lathe. The mating surface of the coupler is machined for a super square to the shaft alignment.
Run-out (shaft deflection - D bends) can also be measured here and if slight,, corrected.
If possible, the clutch flange is also presented. Some shops can also square this or exchange for a flange that has been faced on a similar out shaft.
All of this offers the most straight and vibration free shaft installation.

You were looking for some noise, this should remove it if in the drive line.

 

[brettportzer]

Here is an update on this. Machine shop guy said that the coupling was out by .057 and probably had never been faced. Shaft was out .016. He rebalanced my prop and spin the whole thing up and got it all lined up as a unit at his shop.

Should be good to go.

The prop needing to be done again was surprising to me, we only put about 30hrs on the boat this year, and run pretty slow, and didn't hit anything as far as I know.

Lots of shallow areas around here, including my dock sometimes...

So, I had in mind that my prop was discolored like this because of the mud, the bottom of my rudder is a little weird too.

But, he says it is heat, but doesn't have any idea why it would have happened.

We did the props last year, this is new.

Photo attached...

 

[dsharp]

I would be surprised if heat caused the discoloration. There’s no reason to heat the prop that far out on the blades to remove it. Make sure the key will slide through the key way in the hub when you put the wheel on the shaft.

 

[brettportzer]

I didn’t need any heat to remove it, it is a discoloration that showed up between last spring, when they props where removed to be balanced and cleaned up, and now.

So, it happened while in the water.

 

[rsmith]

Mine are the same. You’ll see a little whack mark from the chisel I use to spread the coupling. The pin is just held in by friction when the slot is squeezed when the bolts are tightened. Clean out the slots with a putty knife to make sure there’s nothing is preventing it from squeezing up. I put cutlass bearings in every year for probably the last 5 years before I replaced the shafts. After I put the new shafts in it’s been 20 years and they are still tight

 

[brettportzer]

Does look pretty much the same, is yours original equipment?