G23 Prop Fell Off .....

[hotrod508]

As soon as it snaps off it almost stops rotation. People don't realize how much drag and pressure there is on a prop. Especially from a weighted boat. Think about how fast your boat slows when you let off the throttle from cruising across the lake?
Off shore boats routinely will have the props heat up to the point that they have to wait on them to cool to remove them for transit. This means especially with the steep pitch of the prop, drag of the water, weight of 17" hunk of metal. The prop will stop rotation within a few several turns. As for hitting a surfer, you have the rudder in the way the back of the boat and the platform! Unless your hanging out below the platform level it would be very difficult for the prop to exit the water, especially being on a downward angle.

I'd say your pretty safe!

[sja]

I find it disconcerting that we haven't had a progress report from cc on this issue. We (as the community of those who have purchased the most expensive wake boat available) are left to share experience and to speculate on the cause of the problem, the factors which could potentially help us calculate the risk of it occurring (engine hours, year, engine type etc) and the potential harm that could result from this sort of failure. By now, I would suspect the company has seen almost all of the broken shafts and should comment on what data they have (even if preliminary)
I would like to start a list of questions that this community would like to know about the problem so one may calculate their individual risk, and so we can at least be reassured that someone at CC is working on an answer. Please add to, subtract from or ignore my list:

1) Is the shaft manufacturer exclusive to CC?
2) what the number of failures have been reported so far and what total number of G-Series boats have been produced?
3) # of failures for each model year?
4) # failures for each engine type ?
5) have all failed by a certain number of hours?

Finally , it would be nice to have an apology to all with a G series boat for having to worry about losing power when they travel to exotic places like Lake Powell, or in my case when planning to go through locks (and hopefully not over the dams) of the Mississippi river.

[scottb7]

Of the 5 questions. I think maybe they would answer the 1st one only. No, come to think of it probably not. People thought I was nuts...Well at least not serious, but I was. Go buy an electric trolling motor just in case, if you can't just throw down the anchor and get help.

[Dukeboiler]

Thanks for all the posts - I agree it is very very unlikely that a sheared prop would hit anyone behind the boat. You guys all bring up great points on how unlikely it is that the prop would hit my rider. The point not brought up however, is the one I'm looking for. I'd like the reason I don't have to worry about a prop shearing off into a ride to be that CC is on top of this issue, knows what is going on, and has taken care of all the impacted boats. Instead I'm left with conjecture on why the rider will in all likelihood be safe if the prop shears.

Again, might be what I'd expect from a commodity mass produced boat - but not the $130k boat I bought for a lot of reasons - one of which was the quality build and reputation of the builder.

Not trying to sound too dramatic - just feel a void in CC's visibility into the cause and repair of this issue - and that's concerning.

[KTM525]

1) Is the shaft manufacturer exclusive to CC?
2) what the number of failures have been reported so far and what total number of G-Series boats have been produced?
3) # of failures for each model year?
4) # failures for each engine type ?
5) have all failed by a certain number of hours?

There is only one answer from CC i would be interested: We found the problem and have send a new shaft to all customer.

Sitting on a lake without prop is a no go ;-)

[Laptom]

It is only an issue for 2 years so I don't expect an answer very fast from CC.
Always a CC addict, but currently not feeling pride of this marketing strategy of complete silence.
Off course they are working "hard" on this issue, but the time frame they are taking seems ridiculous at this point.

[sja]

Always a CC addict, but currently not feeling pride of this marketing strategy of complete silence.

If there is any pressure to at least have CC tell us what is going on, it is in people like you who are on or near the 1000 post club: true long term believers and promoters of their product, who are starting to have doubts.

I suspect the longer they have waited in silence, the more difficult it has become. Because now they would have to not only explain what they know, but why they have been silent on the issue. At this point I suspect that they are just hoping this thread drops off the front page of this forum.

[scottb7]

They don't have to say why they have been silent. They could but they don't have to.

[davidmamato]

you got it, the fractured shafts have come off the 550hp motor and I saw one myself at the shop.

[MI-skier]

This happened yesterday after about 5-10 minutes of driving 23mph while pulling a tube. All sudden a bad vibration started to happen so I pulled throttle back. Applied throttle again and it was still there. Idled into dock and when I was positioning boat into slip I put into reverse a couple times. On the second time I felt a slight thump and lost all propulsion. Raised boat and this is what I saw.

Boat has 50 hours on it and to my knowledge has never hit anything (bottom etc).

Anyone seen anything like this? Frankly, I can't wrap my head around the physics of how this thing just shears off.

Any more pics? Looks like fatigue. And you can't see the bottom left of the shaft. Did the cross section look different there? Like more shrapnel-ish?

[A330Captain]

Im postponing my decision to even consider the G until this is all sorted out.

[Gunners]

No more pics and the boat has already been fixed (although not picked up).

If I recall correctly, the left hand side did look like it had a small slit in it, almost pie-shaped that extended a short distance down the shaft.

I expect to be able to retrieve the broken off section since this happened right at our dock. If I'm able to do so I'll get pics of it and post them.

[sja]

Another post appeared yesterday on Wake world.
2014 G21 with 409PCM with 40 plus hours.
Same story - Vibration, then loss of propulsion.
(He says he loves his G. He reports that Nautique is "aware of the problem and working to resolve" and "taking care of everything")

[nyryan2001]

Another data point to support the infant mortality rate theory... 45hrs

[sja]

Spoke with my CC service guy today. He informed me that the service bullitin issued recently indicates that the problem is with the shaft machining and not the shaft materiel. The slot for the key in some shafts is reportedly "out of spec". They have been informed that by visual inspection they should be able to tell which shafts are at risk of shearing. This sounds implausible given the info accumulated in this thread. Any comments from those more familiar with metallurgy and mechanical engineering??