Mastercraft X23 Broken Drive Shaft

[seattlehd 9]

Just wondering if anyone has seen this happen before... I was out on my friends 2015 x23 with the upgraded 7.4 motor cruising at 30mph with ballast unloaded and 8 passengers in 40 feet of water. We heard a light thunk and the motor reved and we lost power. We quickly realized that we had no power even though the transmission  was engaging.  My friend jumped in the water and found that the entire drive shaft with prop was gone and we were taking on water rather quickly. We were able to keep the boat afloat using bilge pumps and a ballast pump and got towed quickly back to the launch and on the trailer. After our nerves calmed down we started looking into what went wrong and found that the drive shaft had broken all the way at the transmission and apparently shot itself out the back. We are positive we didn't hit  anything and there is no damage to the tracking fins or bottom of the boat. Has anyone heard of something like this before?

[InfinitySurf 302]

Is boat still under warranty? I have not seen a break that close to transmission, but Nautique "G" boats have been plagued with shaft drive breaks the last couple years...think most of those are toward middle or closer to shaft tho. Even heard that they are only covering parts under warranty and owner has to pay install which is around $500 (4hrs labor). Sorry I cannot be more help on specific question...perhaps the same manufacture of shaft on your boat as the G's? Its also possible shaft was damaged/stressed at previous time and just decided to give at that moment...but I lean more toward manufacture defect or conditions are just more than it could take (under designed). I knew newer boats are getting thicker shafts...

[Shaka 146]

My friend had this happen on his X45. I I believe it also cost him his V-drive. The parts and the fixing the damage and the bill was around $10k. 

[Cdifranco 463]

This is why we buy Centurions folks. 

[Chexi 35]

Big problem with the early Nautique G's as noted above until they increased the shaft diameter.    Not sure if the problem is persisting with the newer shaft.  I know that if I bought a G, there is no way I would be paying labor on that work (and my wife would probably insist we sell the boat after getting it repaired).  I have heard stories both ways, so they apparently did try to charge labor to at least some customers.

What size is the shaft on the RI and FI series?  If they did not increase the shaft diameter for those huge boats, it is possible that we might start seeing this on them as well, but perhaps the efficient hull is lowering the amount of stress.  Time will tell.

Edited August 7, 2017 by Chexi

[Chexi 35]

Makes one wonder where those shafts are being made.  Steel quality varies significantly.