Broken Shaft on 2011 Epic 23V

I was out surfing last Sunday when my boat just stopped moving, as if I had dropped it into neutral, but the engine was still hitting the same RPMs. I quickly realized I lost my prop and shaft into 80+ feet of water. To make it even more stressful, I was taking on water faster than my bilge pump could keep up. Lucky for us, we had a buddy one cove over that could pull me back to the ramp while we bailed water.

When I got the boat back home I removed the coupler to find a three inch shaft was all I had left. It looked to start splitting at just aft of the prop key... meaning the shaft broke within the coupler. Nothing else looks to be damaged. The prop must have slipped through the log and right past my double rudder without even tapping the boat or anything else. There are no marks or misaligned pieces as far as I can tell... and I have spent hours staring at it.

I post this here for a couple of reasons...

First of all, I read on the another board that this could happen from improperly seating the shaft into the coupler. They said that using heat to expand the coupler causes the shaft to weaken and eventually break. With my boat's 8.1L engine and high torque prop, I could see there being a better chance of this happening than with a lower torque setup, but it still sounds strange. I am wondering if anyone can confirm that heating up the coupler to seat the shaft could cause the shaft to weaken. I hear the better way to seat the coupler is with a compression method - not sure how that is done. Anyone know anything about this?

Second, I am wondering if I can find another 2011 Epic 23V owner out here that happens to know the dimensions of their shaft and prop. My buddy has an '09, and I was able to grab his dimensions, but I am not sure if they are the same. I contacted Epic yesterday, but I have not received a response ... every day I don't have the part ordered is another day I will not be on the water. I am sure many of you know how that feels! Any help would be greatly appreciated!!

Also, if the log, strut, seal and everything else looks perfectly straight and without damage, can I just slide a new shaft in and bolt it on? I know about ensuring the coupler has 0.03 ml or less of tolerance and how to move the engine to adjust. I am more concerned about the log, for example. I can hardly get to it, and I would rather not mess it up, if it is working. But at the same time, I want this done correctly. Any advice there? How do I know if there is something wrong down there? I tried to snap a picture of the shaft hole... looking from the outside in.

And lastly, this is a tapered coupler and it doesn't look to be in that bad of shape. Can I (should I) reuse it? Is there a risk in reusing the coupler, or is that standard practice provided there isn't a lot of metal missing. As you can tell from the picture, it has a fair amount of rust on it, but it seems to be only on the surface.

By the way, I am not bashing Epic. I know people have a lot of opinions about Epic and that's great. But the shaft in question is 1 1/8" thick (I think) and shared by some of your more recognizable brands. Although I just purchased this boat last fall, and I am the third owner, I think this particular shaft was at least re-installed if it is original to the boat. I say this because I found two smaller flat washers on one of the four coupler bolts, where the other three had the factory original, larger split washers. It makes sense to me that someone could have improperly seated this shaft, causing it to weaken and eventually break, which would exonerate Epic, in my opinion. Hence the question about the proper way to seat a shaft into the coupler. Other conspiricy theories are welcome... provided they do not require a tinfoil hat.

My buddy had this happen 2 or 3 times with his '07 Epic. The last time was out at Lake Powell and the water was 200' deep! Turned out that it kept happening because the shaft was not aligned properly and once it was aligned properly, never had an issue again.

That is a thought... Maybe I didn't have a heat/seating issue, but an alignment issue... Did your buddy do the alignment himself? How hard is it to move the motor around and achieve a perfect alignment, I wonder.

Well, Epic got back with me. They said my shaft is indeed a 52.5" x 1 1/8". But they use a 14 x 14 1/4 prop (Acme 1433 or 1847 if I want a 0.150 cup instead of the 0.105 cup). Hmmm looks like I have some Googling to do...

He aligned it and it was a pain in the azz! That 8.1L is a heavy mofo and it was 90+ degrees out and we there wasn't any shade! It took awhile but he finally got it. He lost the first prop and shaft and then the second and third one's got hung up on the dual rudder system and he was able to push it back into the hole and tie it up to keep the boat from sinking.

Update:

I purchased a prop from Nettle Props (http://www.nettleprops.com/) and my shaft from Bakes (http://bakesonline.com/). The prop was ridiculously awesome... They called me back within an hour of placing the order online to tell me that I don't need to pay for the expedited shipping because he can drop-ship it from a warehouse near me. I saved a bunch of money and got the prop super fast! I would highly recommend Nettle Props (and already have). The shaft was a little more of a problem. I ordered it online on a Friday morning. On Monday I hadn't received shipping information, so I contacted Bakes. I worked with Andrew @ Bakes, who was very helpful. I told him of my timeline and asked him what we can do to make this happen... Andrew did the rest. Andrew made sure the shaft was in my possession as soon as possible. He went out of his way, to say the least. Good guy, good company, good product... all in all, two good purchases... total for the prop and shaft: just under $1K in goods, shipping and taxes.

Then I went to put it in,,, I think Timmy and his buddy must be muscle heads or something (no offense), but I couldn't get that engine to budge much from pry bars. It's bad enough that there is like no room to get to the port side aft motor mount, thanks to the coolant system. But the engine weighs a little more than a crap load (that's the technical term). We ended up manufacturing an engine lift from a hydraulic jack, chains and an Olympic size weight bar... total rig job, but it worked!! I would highly recommend someone borrowing/buying/stealing an engine lift to do this job. Once we had our "lift" rigged up, it was pretty simple... just a bunch of playing with it to get it to align. We would determine where it was off, lift the motor, raise or lower the nuts on the mounts, then drop the motor and re-measure. After we figured out what needed to happen, doing it was pretty easy. The best resource I found was this Mastercraft how-to video: https://youtu.be/MkzemrcgZ48

Oh, and one last thing... When I put in my new shaft, the aft of the motor was too low, causing a (large) gap at the top of the coupler. I think that means that the old shaft broke because the motor was not aligned - not proof, just a logical assumption... if the motor didn't change, and the two shafts were both strait, then the motor was not aligned when the old shaft broke.

Good job! And great video link, my suggestion to anyone facing similar issues is follow it to the T! Your issues here are common. Engine mounts "settle" as they become worn, typically resulting in the heavier part of the engine(towards the back of the boat in a V-drive) sitting lower than the front over time. Everyone should get their alignment checked at their first 20hr service but often this is neglected or done incorrectly and then 5 seasons later there is problems. For the long run it is good practice to check your alignment every 100hrs if you use your boat sparingly and every 200hrs if you are getting a lot of time on the water. As the boat ages the engine mounting wear is less of a concern... And some would suggest longer intervals of checking but it really is a simple check once you know how and EVERY inboard service shop should be masters at this. If you boat is in the shop for anything else, INSIST that they check and adjust your engine... Improper alignment causes broken shafts, blown strut bearings and leaky shaft logs so it is ALWAYS a good idea to make sure things are staying aligned over time as it will save you BIG in long term repairs. I've seen 30yr old boats with original strut bearings, shafts and logs because the owners ALWAYS kept it aligned well.

One of the easiest indications that you might have an alignment problem(QUICK TIP) is to visually inspect the shaft from the bottom of the boat and make sure it is centered with the chat log hole. If it is low, high, left or right of the hole then you may have a problem. Also, if you can't easily turn the shaft by hand turning the prop (when in neutral with the engine OFF, of course) than you might be misaligned with the strut which would require engine realignment.

Have a GREAT season with your boat Chris!

Originally Posted by TX_Chris

I think Timmy and his buddy must be muscle heads or something (no offense), but I couldn't get that engine to budge much from pry bars.

LOL! No, not at all. That engine is ridiculously heavy and took hours to position correctly, I apologize if I made it sound like it was easy because at no point was it ever easy. Glad you got it all fixed up.

When I picked up my boat the mounts were loose and were not noticed by the previous owner, so I knew I had to check the alignment at some point. As well, the prop and rudder had taken a good hit (not the one that I did -see my fix write up) that caused the shaft to bend slightly, which in turn caused the strut bearings to wear unevenly and just like Chris said, there was binding when rotating the prop by hand. It also had a slight vibration that didn't go away. I was expecting it to possible break, but it never did (I knew I was going to have to cut it off to remove it). Fast forward to 2 winters ago I was forced to replace the shaft as I could not separate the transmission coupling from the shaft. It was cold welded to it from previous damage. With the new shaft, bearings, and alignment it is smooth as silk.

Yes, the engine was a PITA to move around, especially with it being the big block and the old style mounts. Small changes go a long way and if the adjustment nuts are blocked by the engine, getting the wrenches in place can be difficult.