10m Express â€“ Prop Shaft Replacement

Natchamp · Post by **Natchamp** » Mon Sep 05, 2011 11:21 am

Gents,

It looks like Iâ€™m going to need to change out my prop shafts on my 10m Express project. The shafts are pitted and have some worm holes. I was planning on installing some new cutless bearings anyways but now Iâ€™m looking at new shafts, stuffing boxes, etc as well.

Does anyone know the length of these shafts? I know they are 1.25â€ with a single taper. What I donâ€™t know is the length which I need to order the new ones. Iâ€™m not sure if I will be able to get the old ones out without cutting them up (see below).

So far I have been able to get the prop off. I made a cutless bearing removal tool (pic below) so I could remove the bearings with the shaft still in place. However, I tried removing the bearings this weekend and they definitely donâ€™t want to come out. Yes I removed the set screws. Any ideas? If I canâ€™t get the bearings out I will either have to cut the shaft or take the struts off.

I also made a shaft coupler puller (pic below). I tried using that also and I need to get some longer bolts. From what I can tell so far, that thing definitely does not want to come off and there is a chance I will have to cut the shaft there as well. The coupler diameter is too large to come out with the stuffing box all in one shot.

So, here are my questions:

What is the length of the shaft and if I order a single taper at the appropriate length is that all the information I need?

Any ideas on how to get the bearings out? Iâ€™m reluctant to add heat because of the plastic/polymer aspect of the bearing.

Should I avoid removing the struts or is it pretty straight forward to do? I checked and I do have access to the backing plates. Since the motor is still in, I can use that for re-aligning the struts?

If the shaft coupler is pressed on so tight, so in the heck am I going to install it when putting the new shafts in?
Any additional words of wisdom?

prowlersfish · Post by **prowlersfish** » Mon Sep 05, 2011 11:39 am

The shafts will come out with the cutlass bearing in place . the coupler should have a set screw or bolt on it a few had roll pins . Heat maybe needed . I would not order new shafts with out measuring your old ones .

Natchamp · Post by **Natchamp** » Mon Sep 05, 2011 1:05 pm

Hi Paul,

The way my boat is on blocks, getting the shafts out in one piece without first removing the bearings isn't going to happen. I could jack up the boat more but I'd rather not go there.

RWS · Post by **RWS** » Mon Sep 05, 2011 5:51 pm

Mark,

With TWO struts per shaft, IMHO I'd avoid distrubing them and creating potential alignment issues down the road.

Kudos to you for going about this project in the right way. You certainly have the background for pulling this project off nicely, with the result being a very dependable vessel that should provide you with years of enjoyment.

If you cut the shaft with a sawzall you could still determine the length of replacement shafts AND then press off the old couplers.

Given the deterioration of your shafts it's a safe guess that the boat's zincs were neglected and that you should carefully check for other evidence of galvanic corrosin that could have manifested itself elsewhere, although I cannot thnk of anywhere else other than the rudders, nonmaleron thru hulls and seacocks. (whose replacement you have in process.)

Be sure to confirm the validity of your bonding system.

RWS

Big D · Post by **Big D** » Mon Sep 05, 2011 8:23 pm

Lift the boat higher and take the shaft out in one piece. If you need it higher to get the shaft out, you'll need it the same way to get a new one in so do it now. You seem to be able to make tools you need so leave the coupler attached to the tranny flange, remove any fasteners around the coupler that fasten to the shaft, construct a good heavy hammer puller with a feamale thread on the end to match the thread size of the shaft. Screw the puller onto the shaft and bang her back. She'll come right off the coupler. Then unbolt the coupler and remove the bearing. Do a search on cutlass bearing removal, there is a copy of a good article that shos an easy way to do it by cutting with a hack saw (don't use sawsall), colapsing the bearing and removing it.

prowlersfish · Post by **prowlersfish** » Mon Sep 05, 2011 8:31 pm

Natchamp wrote:Hi Paul,

The way my boat is on blocks, getting the shafts out in one piece without first removing the bearings isn't going to happen. I could jack up the boat more but I'd rather not go there.

So how are you going to get them back in ? and why would the bearing have any effect on raising the boat or not ? I have changed many shafts and never had to remove the bearing . Am I missing somthine here ?

Big D · Post by **Big D** » Mon Sep 05, 2011 8:58 pm

Ditto Paul. You deffinately don't have to remove the bearing first to get the shaft out. The shaft will simply pull through the bearing. Easier to pull the bearing without the shaft in the way. I'm assuming you want to pull the bearing because it is worn and needs to be replaced....yes?

RWS · Post by **RWS** » Mon Sep 05, 2011 9:43 pm

prowlersfish wrote:
Natchamp wrote:

<SNIP>

I have changed many shafts and never had to remove the bearing . Am I missing somthine here ?

Could the issue here be that the shafts are so long that they require two struts?

RWS

RWS · Post by **RWS** » Mon Sep 05, 2011 9:49 pm

For what it's worth, when we did the refit to diesel we increased the shaft size to 1.75".

While this WAS overkill, it allowed us to replace the 4 factory struts with 2.

I also bought a new spare shaft.

Here's the data on it frm the invoice I just looked up:

A-19 1 3/4" 90.25" long stainless shaft

This will be DIFFERENT than yours as these engines and downangle transmissions are totally different, but it may give you an idea.

RWS

Big D · Post by **Big D** » Mon Sep 05, 2011 10:18 pm

RW, the two struts shouldn't make a difference with removing the shaft. It will still pull through albeit with a little more force required unless the two struts are way out of alignment.

prowlersfish · Post by **prowlersfish** » Tue Sep 06, 2011 6:49 am

Big D wrote:RW, the two struts shouldn't make a difference with removing the shaft. It will still pull through albeit with a little more force required unless the two struts are way out of alignment.

Correct

Natchamp · Post by **Natchamp** » Tue Sep 06, 2011 10:58 am

Guys,

Sorry for not being clearer in my description. Assuming I can get the coupler removed, the main problem for removing the shafts in one piece is the height of my boat. As you know the shafts come down/out at an angle so they will hit my concrete driveway.

My thought was to remove the cutless bearings, thus allowing a greater â€œfreedom of angleâ€ for the shaft. If the bearings were removed there would be @ Â½â€ clearance around the perimeter of the strut. This would allow the shaft to be more parallel with my concrete driveway versus the rigid angle of the struts. Make sense?

For new shaft installation the process would simply be reversed. The bearing removal tool I made can also be used to press in the bearings.

The problem is the bearings wonâ€™t come out, even with the super duper removal tool. So I can either cut the shafts, remove the struts or jack up the boat. If I canâ€™t get the coupler off I will need to cut the shafts no matter what. If I do end up cutting the shafts I can still get length measurements from them by allowing for kerf width of the saw blade.

My thought on removing the struts was that everything on this boat (so far) has needed attention so why assume those wouldnâ€™t benefit from re-bedding. If I used the new shaft as an alignment tool and simply gooped the struts with 5200/4200 and let everything dry/bond with the shaft holding everything in alignment then why wouldnâ€™t that be correct? I would bet the original strut installation method would be the same process. Iâ€™ve never done this so if you tell me Iâ€™m all wrong thatâ€™s ok, I wonâ€™t take it personally. Another dangerous assumption (imo) is that the struts are currently aligned perfectly. How do I know that the previous owner didnâ€™t hit a big rock or something that knocked the strut/s slightly out of alignment?

On a side note, unrelated to the above removal/installation issues I canâ€™t figure out something about the overall shaft design. The way I see it, there are a lot of axial loads put on the prop shaft during use. When running in forward motion the prop is essentially trying to push the shaft forward which is of course transferred to the transmission/engine mounting and then through the hull pushing the boat forward. Rearward motion is just the opposite with the prop trying to pull the shaft rearward. All of this axial force being transferred is completely dependent on a secure attachment of the shaft to the transmission/coupler. However, the axial attachment of the shaft to the coupler is only via the four perpendicular set screws. I havenâ€™t seen what the shaft looks like with the coupler off but Iâ€™m assuming there are no holes in the shaft to receive the set screws and the set screws only provide tension based adherence. Please remember I am not talking about any torsion forces at all as all of those are handled via the key ways. Iâ€™ll phrase the question like thisâ€¦ When you put your boat in reverse and hit the throttle, what prevents the propeller and shaft from ripping themselves out of the boat?

RWS · Post by **RWS** » Tue Sep 06, 2011 11:44 am

Mark,

As a fellow 10 meter express cruiser owner I can offer a coment on the struts:

When originally surveyed for purchase, the surveyor noted that the fasteners attaching the struts to the hull appeared to be missing nuts inside the hull, requiring attention.

The fact is that there are no nuts inside the hull, there is a backing plate that is threaded for each of the fasteners.

Just a bit of info hat might be bvaluable to you should ou need it.

The ony other thing I can offer is that in my case several of the hardwood oak engine support blocks were in less than good shape and the Crusader factory adjustable engine mounts were FROZEN beyond any ability to adjust and while one engine was SLIGHTLY out of alignment, it could not be adjusted without significant investment of cost and time.

When we pulled the engines out we found lag bolts fastened those wood blocks tthe stringers, several f which were stripped out.

Just wanted to pass on some information based on my own experience, FWIW.

RWS

larryeddington · Post by **larryeddington** » Tue Sep 06, 2011 1:05 pm

You can pull the couplers somehow. I used a KD puller, the plunger part was fine thread which gave it a lot more pull. However it was a real pull using a large breaker bar, but succeeded.

Bob at Beacon says these are refered to as a light press. Maybe so but what causes the issues is burrs from the dimpling of the set screws which must be over come. Cleaned up would go back on much easier.

Good Luck.

BobCT · Post by **BobCT** » Tue Sep 06, 2011 4:36 pm

I have used a socket and long bolts to "press" the shaft out of the coupling. Basically, tighten the bolts a little while the socket is sandwiched between the shaft and the trans coupler. You'll need to stack washers to make it shorter and shorter and keep the socket centered.

It's a little tedious but works fine and no risk of damage.

To reinstall, don't bang the flange on inside the boat. Line it up inside, go to prop end of the shaft and using a block of wood and a small sledge, drive it into position on the flange. It helps to have someone inside to tell you when to stop.

Bob