Shaft alingment

[brodiecolton]

How important is the shaft alignment coming out of the hull of the boat? The boat is an Infinity ZX1 (sorry for posting on a nautique site nowhere else to go). Shaft is a V drive. no vibrations seems to run fine boat has less than 100hrs. however, looking under the boat the shaft is almost touching the cover plate it appears it has touched a little, there is a slight wear on the shaft nothing significant. Does the shaft move or flex when in gear or under a load. just wondering how serious this is. not many tournament boat places near by to get my boat looked at and the ones that are would prefer not to touch an Infinity

[8122pbrainard]

RE: Shaft alingment

Shaft centering at the log/hull hole/stuffing box is the least important point. The key points of concern are the shaft to the cutlass in the strut and the shaft coupling to the V drive which is the engine alignment.

[richard]

RE: Shaft alingment

looks like you have a blended struct, can the propeller turn freely by one hand?

[SkiTower]

Re: RE: Shaft alingment

looks like you have a blended struct,

PDT_018

bent strut?

Maybe the plate isn't aligned and the shaft is...

[brodiecolton]

RE: Re: RE: Shaft alingment

prop turns ok can't recall ever hitting anything except the boat lift bunk once barely(no damage to the prop). like I mention no vibrations only thing I have noticed is a high pitch squeal when the boat is put into gear at low idle as soon as I give it any gas it the squeal goes away. I thought it might be harmonic from the prop or the transmission. just wondering how concerned I need to be about alignment. pretty sure the shaft is not bent I think the camera makes it look like that. really want to go skiing tomorrow.

[Andrew]

RE: Re: RE: Shaft alingment

A squeal at low speed is usually an indication of something being off with the strut bearing. Check to see if part of a ski rope or fishing line has been wrapped around the shaft and worked its way into the bearing housing. Also check for random things like chunks of wood and other debris. If all of that checks out, the bearing itself may be worn....

[AirTool]

Re: RE: Shaft alingment

Maybe the plate isn't aligned and the shaft is...

yea...clearly the plate is off. Looks like about 3/16" clearance between plate and tunnel over on left side of pic and greater than 3/8" or 1/2" over on right side of plate. I'm thinking either 1) grind the hole bigger, 2) build a new plate, or 3) glass up the holes in the hull and dirll some new ones.

I'm not sure about 3 without seeing the inside.

So....grind the hole bigger for now and fix it right next winter.

AirTool

[Chris4x4Gill2]

Re: RE: Shaft alingment

Maybe the plate isn't aligned and the shaft is...

yea...clearly the plate is off. Looks like about 3/16" clearance between plate and tunnel over on left side of pic and greater than 3/8" or 1/2" over on right side of plate. I'm thinking either 1) grind the hole bigger, 2) build a new plate, or 3) glass up the holes in the hull and dirll some new ones.

I'm not sure about 3 without seeing the inside.

So....grind the hole bigger for now and fix it right next winter.

AirTool

I think it would be easier to put a slot in the screw holes on the plate. Keep the ID of the through hole the same.

[8122pbrainard]

RE: Re: RE: Shaft alingment

You do not want to blow the tail end of that V drive trans!!! Yes, misalignment will do it. You had better do a alignment proceedure to check both the strut to the hull/log and then the egine to the shaft.

[TravisFling]

RE: Re: RE: Shaft alingment

I wouldn't run that without checking it out first. These things need to be centered within thousandths, this is visible, and very much so.

[TravisFling]

RE: Re: RE: Shaft alingment

these things = engine to tran to shaft, not necessarily the pass-through, but that would be odd to me that it's off center that much. Whine= bad, by the way. You should get that checked out.

[M3Fan]

RE: Re: RE: Shaft alingment

The "plate" is probably not just a plate. It's probably the base of the shaft log. So, your packing gland would also be attached to that same piece and would be really misaligned with the shaft. I'd definitely check that out. If the prop spins freely it may be because the strut bearings are already worn in unevenly based on the misalignment. The ZX-1 is a sweet boat- a V-drive in the center of a small ski boat. Those things accelerate unlike any other boat. It's amazing.

[jwchapman]

RE: Re: RE: Shaft alingment

Looking at the picture closely - the shaft looks centered in the fiberglass tunnel, the plate looks skewed to port - anyone else see this?. I would first check to see if the triangular plate is attached to anything (packing gland) or if it is just a cosmetic cover plate. If not attached to anything else, and not touching the shaft, I would think you can ignore it and work you way through the driveshaft components and bearings. Please let us know about this - I am very curious whether the plate is attached to anything - if so, it is odd it would be so far off center.

If it is not attached - I would go back to pbrainard's posts and start checking the alignment. There are lots of good posts here on how to do that.

The high squeal is a concern - but could be a number of things - including transmission, bearing, packing gland or a belt. Good luck with the search.

[DavidF]

RE: Re: RE: Shaft alingment

I think the condition pictured is not that uncommon. If the shaft is not bent and the alignment at the coupling is good and the shaft is straight in the cutlass bearing, then do not worry, you are good. The rubber hose coupling at the shaft log can compensate for the condition pictured.

[brodiecolton]

RE: Re: RE: Shaft alingment

The picture angle makes the plate look off center. the plate is pretty well centered. Just drove the boat today with no vibrations and the squeal actually happens when I take it out of gear and the boat is slowing down and the motor is idling down. I think it is a harmonic noise from the prop (four blade oj that has had work done on it.