Prop shaft to shaft log alignment

[bubba_tiger]

Got under boat and noticed my prop shaft was way off center to shaft log:

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This is probably common knowledge, but do I need to disconnect the shaft seal (I've got PSS) from log before going through the trouble of realigning everything else? I've already disconnected the 4 bolts from the couplings, but the prop shaft doesn't seem to want to move very easily and I did not want to break anything. I've found tons on info on aligning the prop shaft at the couplings (thanks Moomba Forum), but nothing on the shaft log. Thanks,

[DOCDRS]

If its not rubbing dont worry. Do check your shaft coupler to vdrive coupler alignment. ie. your engine alignment. Wet your cutlass bearing to free up the propshaft. Then check the lateral play, if its out and can be centered then you have to slide the entire engine over to maintain proper alignment. Your strut could be bent. your propshaft is not supposed to line up with your rudder. Confused yet?

[bubba_tiger]

Thanks for the advise, and it makes sense. Found out the strut is new (installed in Jun '17). The previous owner did not try and center the shaft to log when installing the strut. The coupling is aligned fairly well. All the videos I've found state you should be able to slide a medium sized zip tie between shaft and outer hole, which I cannot.

Also a mastercraft website stated that the shaft not being centered will cause abnormal and excessive wear of the packing, as the shaft will essentially be "pushing against one side" of the ID of the packing.

Thoughts? It's just a lot of work and/$$ getting everything out to align/straighten the strut if the only risk is causing excessive wear on the packing.

[DOCDRS]

The coupling is aligned fairly well. All the videos I've found state you should be able to slide a medium sized zip tie between shaft and outer hole, which I cannot.

Also a mastercraft website stated that the shaft not being centered will cause abnormal and excessive wear of the packing, as the shaft will essentially be "pushing against one side" of the ID of the packing.

What does fairly well mean? You have to take the four bolts out as well as loosen the hull boot clamps and the boot, and pull it off the hull side to take any stress out. Then see where the strut places the shaft horizontally. The shaft will drop vertically due to the weight of the shaft and coupler. The middle of the lateral movement is where you want the shaft, otherwise you will get cutlass bearing wear. This is most important due to the lateral forces when steering the boat. Dont be afraid as the mechanics probably dont even understand this and all they may care about whether the alignment is within 5 thou. ( you should be able to get it within 1 thou quite easily.) And not how things actually work. If the strut is off angle when it was mounted then you want to know if you can align the motor with it. Since the vertical angle is fixed we have to hope it is within the tolerance. If your vdrive coupler is in line then put the bolts in and check the spacing at 3 and 9 oclock.
if its close , then check your shaft thru hull clearance and now you will know if you have a problem and whether the strut should be remounted. Plus if it was replaced then that means it was hit and you need to know if your shaft is true.

[bubba_tiger]

Doc, fairly well was touching at 12 oclock & 3 oclock. I could get .0025 in at 6 oclock & .0003 at 9 oclock. Bolts have been removed, and I do not believe the shaft is bent because the spacing remaining the same with I rotate the shaft at 90 & 180 degrees. I did not remove boot clamps, but I will take your advise and see what I have. Thanks!!!

[DOCDRS]

So if you move the front of the motor in the 3 oclock direction will that help more center the shaft? Im assuming you have a vdrive

[bubba_tiger]

Yes I do have a v-drive and yes sir, moving front of motor in 3 oclock direction will help the coupling alignment. But first I want to get the shaft in the in the center of the shaft log while putting the least amount of stress on the cutlass bearings.

[bubba_tiger]

What does fairly well mean? You have to take the four bolts out as well as loosen the hull boot clamps and the boot, and pull it off the hull side to take any stress out. Then see where the strut places the shaft horizontally. The shaft will drop vertically due to the weight of the shaft and coupler. The middle of the lateral movement is where you want the shaft, otherwise you will get cutlass bearing wear. This is most important due to the lateral forces when steering the boat. Dont be afraid as the mechanics probably dont even understand this and all they may care about whether the alignment is within 5 thou. ( you should be able to get it within 1 thou quite easily.) And not how things actually work. If the strut is off angle when it was mounted then you want to know if you can align the motor with it. Since the vertical angle is fixed we have to hope it is within the tolerance. If your vdrive coupler is in line then put the bolts in and check the spacing at 3 and 9 oclock.
if its close , then check your shaft thru hull clearance and now you will know if you have a problem and whether the strut should be remounted. Plus if it was replaced then that means it was hit and you need to know if your shaft is true.


UPDATE: I had already taken the bolts out, and I just loosened the boot clamps and pulled everything away from the shaft log. The shaft still wants to remain in the upper right side of the shaft log. I could have a bent shaft but I do not believe so because when I first started checking the coupling alignment, the gap spacing never changed when I rotated shaft.

Any advise?? Do I just need to take it in to get strut aligned (if that's possible)? Thanks

[DOCDRS]

If you rotated the shaft and all tolerances did not change , then your shaft is not bent ( at least from the strut to the coupler. If you are still up and to the right and not touching and see no wearing on the shaft I wouldnt bother. It may be this way so the propshaft can be pulled out past the rudder. AFAIK the only way to center it is to reset the strut. A big PITA if nothing is rubbing. Im pretty sure most boats dont have the shaft centered in the shaft log , but I could be wrong.