2006 Avalanche Prop Shaft

[kiddhardware 0]

I have a 2006 Centurion Avalanche with a Scorpion 330. A few weeks ago I hit an underwater rock going between 11 and 13 MPH and that took off about half of two blades of my Acme 1579. The rock formation wasn't solid so my prop most likely broke apart after being hit. I replaced the prop and I'm getting vibration going above 5 MPH and the vibration is not coming from the steering wheel. I called a few shops, with fingers crossed, hoping I could get in before Labor Day Weekend. A few didn't want to do the job because of how hard it is to get to the prop shaft. One guy even told me that my strut was probably bent too. I inspected my strut and I don't see and dings or nicks that indicate it hit something. I also inspected the shaft coming out of the boat and it has shifted to the right side of the hole. Dial indicator show shaft at .005 off. Not sure if it was mounted very well so I'll re do it with the prop off. Also, looking and the shaft seals, both side of the seals are pressed to the right side. 

1. Can I loosen the motor mounts and see if I can nudge the prop shaft closer to center of the exit point on the hull? 

I've had by boat in the shop twice for preventive work. One was for replacing Cutless bearings and the other was for the shaft seal all within the last 100 hours.

 I have a walk through transom so I only have access to one side of the motor and I cannot see the drive shaft or the nuts to the strut. I've seen a lot of posts on Centurioncrew about removing the drive shaft but I haven't seen much on how to get to it. 

1. Could I unscrew the motor mounts and use a hoist to lift the engine 6 or more inches? Would that be easier than moving the v-drive? 

Thanks, 

Shane

 

 

 

[rhino89523 34]

I am not really sure the exact question, but I have the same boat and have taken the shaft out and it wasn't that big of a deal. The shaft itself if it was bent could be straightened by my prop guy, he has the full truing stand for doing it and I used him on my brother-in-laws boat when he hit hard. 

So if it was me the shaft is supported by the cutlass bearing in the strut, if it has shifted up top it probably shifted your motor mounts a bit. I would undo the coupler from the V-drive to the shaft then rotate the shaft and inspect the cutlass bearing for play. If I could figure out a way to attach a dial indicated caliper to check the shaft for straight I would do that, if not it is pretty easy at that point to remove the shaft completely. Just put a socket or something between the two coupler halves and use some longer bolts and it will separate the coupler from the shaft. Remover your prop before doing so then the prop just slides out...some boats you may have to remove the rudder but that is pretty simple as well and is easy to get to from the locker. Then I would either roll the shaft across my wife's glass table to check for straight or I would run it down to the prop guy.

If you know the shaft is straight then you need to align the v drives output flange to the other half of the props flange or coupler. If memory serves you are supposed to get it within .003 max....that is pretty square or you will wear out cutlass bearings or your shaft seal. If it were me, if you are this deep and don't have a drip-less seal already installed...do it.  There are videos on shaft alignment and it is fairly simple, just takes a little patience and you ar doing the feeler gauge check blind...you cant really see what you are doing. Mine was perfect on the up and down and had moved side to side. The side to side adjustment is done with a crowbar...for real. you have to loosen the sleeves on the motormounts, hit them with some penetrating oil because they can be a little stubborn to slide. while prying on the one side you may need to tap on the other one to get it to wiggle. Getting something within .003 with a crowbar is where the patience is required. Up and down adjustments are done with a wrench on the motor mounts and is easier. Take time and you can get it.

I wrench better than I type, it took me a couple hours to do mine, I was just doing cutlass bearings, dripless seal, and then aligning the motor...it took me 20 minutes to type this reply haha

 

[kiddhardware 0]

Thanks for taking the time and effort to respond. I took a dial indicator to the shaft and it's .030 toward the prop and .020 before the prop strut. Both the shaft and the strut are bent so I no longer suspect that I need to adjust the motor mounts. I removed some cooling hoses from the engine and the v drive and I can now feel the Walter shaft coupler and there is plenty of space for me to remove the bolts. Hopefully the coupler won't be too hard to pop off and the shaft key hasn't been compromised.  

[rhino89523 34]

That was the part I used a socket. I separated the coupler into 2 halves, I put a socket on top of the shaft after removing the nut, then I used longer bolts and squeezed the two halves together and pushed the shaft out.