Drive Shaft Centered?

[embo]

So, those of you that have access to your boat, would you be kind enought to take a look under it and see if your drive shaft existing the bottom of the boat towards the prop is centered in the hole or if it is slightly off center and if so, where? Off center description would be something like it's on the right side of the hole about 3 o'clock position, or it's down at 6 o'clock position.

Wondering if almost all the boats out there have drive shafts that are slightly off center or if most are centered up.

And if the drive shaft is off center, is this a BIG deal? If so, what should be done?

[bobbysky]

As long as the shaft is aligned to the v-drive it doesn't really matter where it goes through the hole in the boat. When they mount the strut shaft it might night be perfectly inline with the hole causing a minor shift in the engine to get it aligned thus putting it a tick of center in that hole. So I wouldn't be to worried about it if yours is off center.

[boatwakes]

Are you referring to it being "centered" visually in the fiberglass mold or the actual stuffing box with the hose attached to it? If it's just the mold then it's no big deal, if it's the stuffing box then read on.
If it's off center in the stuffing box it is a big deal. It absolutely matters where the shaft passes through the hull (stuffing box) as the hose securing the stuffing box has a tolerance and the dripless packing gland will leak with undue stress caused by misalignment, not to mention the strut bearing AND the internal v-drive damage that WILL occur due to misalignment. Where the driveshaft coupling and the v-drive coupling mate has an alignment tolerance of .004" as an industry standard in order to keep vibration and parts replacement to a minimum. The stuffing box is designed on a computer to be aligned with the driveline angle so the driveshaft will pass through it as close to center as possible. If you can visually see that the driveshaft is not centered in the stuffing box and the hose is stressed, you must correct the situation if you want to have trouble free operation.

[boatwakes]

Alignment through the stuffing box is a pretty big deal. Before I start on my soapbox, could you post a pic of what you're dealing with? Driveline geometry is essential to both v-drive and hull health and if it's not correct, HUGE problems will arise.

[jake's02-22i]

Alignment through the stuffing box is a pretty big deal. Before I start on my soapbox, could you post a pic of what you're dealing with? Driveline geometry is essential to both v-drive and hull health and if it's not correct, HUGE problems will arise.

WOW. Thank you for that knowledge. We had that problem at the end of last year and have never fixed the problem. We hit a log, got a new prop and packing seal but that was it and it still leaked through the packing seal after retightening it. We also haven’t run the boat very much so that is good but our dealer has been a PITA to work with. Mainly because he is very condescending when he talks to me, and it pisses me off. His standard answer to everything is bring it in and we will look at it. Dealer is 1.5hours away.

[embo]

Yes I will post up some pics for sure. What is a "stuffy box"?

On the road at the minute but will post in a couple of days. Would really like to get feedback on this issue. Should the prop turn very easily or take just a bit of effort?

[TRD]

It absolutely matters where the shaft passes through the hull (stuffing box) as the hose securing the stuffing box has a tolerance and the dripless packing gland will leak with undue stress caused by misalignment, not to mention the strut bearing AND the internal v-drive damage that WILL occur due to misalignment. Where the driveshaft coupling and the v-drive coupling mate has an alignment tolerance of .004" as an industry standard in order to keep vibration and parts replacement to a minimum. The stuffing box is designed on a computer to be aligned with the driveline angle so the driveshaft will pass through it as close to center as possible. If you can visually see that the driveshaft is not centered in the stuffing box and the hose is stressed, you must correct the situation if you want to have trouble free operation.

Where did you find this?

I had my boat out this wkend and w/ 1000#'s of weight on the boat I was getting vibration. I had to go at FULL throttle to get the boarder up. Once I planed off it was fine, only during throttle up.
I am "Hoping" that it is just last years gas. I just went out and indicated my shaft. TIR is about .001" best I could tell. Play up and down (towards the ground is about .006". In the middle of the shaft I was getting about .010", but there is flex in that area. I don't think this is true play. I just could get the indicator down by the stuffing box to measure across the width of the boat. I hoping this ok, but I am outside the .004" tolerance if that is what you are saying. I just don't see .002" giving me the amount of vibration that I had. I hope! Note w/out weight no vibration at all, boat was fine. Also I have a DD boat. Could I be right about the gas, I will have the boat out again this wkend. I am going to full it up, change the water/fuel sep. and see what happens.

Any thought?

Embo, I posted some pictures of my shaft a long time ago. Mine is offset from the factory for ease of removing the shaft if needed I think. Here is the link. Hope this helps, but your boat is a 2005 and I don't know if this applies to you. Maybe someone else can help w/ that.

http://www.tigeowners.com/forum/show...&highlight=trd

[boatwakes]

All posted questions are answered in this response. Prop should turn out of the water with just a little force, in the water, easily by hand.
TRD, the way you indicated the shaft is just basically measuring the theoretical flex of the driveshaft, the coupler faces are where the measurements are taken. Here's how you do it: loosen the bolts on the coupling, all four, and separate it slightly. Use a feeler gauge and place it in the gap between the couplers, anywhere around the circumference and pull the couplers back together. This gives you your starting point for measurement. Slide the feeler gauge out and without turning the drive shaft, insert the feeler gauge at multiple points around the coupling. There should be tension on the feeler gauge at all points measured. If not, the motor mounts have adjustments using the lower nuts on the posts. There are four motor mounts so there are 4 points of adjustment to get the alignment right. If it needs adjusting, loosen all 4 of the top lock nuts on the motor mounts and start by half turns on individual bottom nuts. It will take a while so don't worry that you're doing it wrong.
As for the stuffing box, this is the packing gland where the drive shaft exits the boat. Every shaft driven boat has one and every rudder post has one. Our driveshaft packings are what's called "dripless" and use exhaust water pressure to maintain liquid lubrication and cool temperatures above speeds of about 13mph or 12knots as a vacuum is created at those speeds at the stuffing box. If it's leaking, the seal is obviously comprimised either from misalignment or seal failure (burning up). If you hit a log hard enough it's possible the strut got bent too. You can check real quick for alignment issues by looking at the strut bearing (also called a "cutlass" bearing). The propshaft will have a slight amount of play at the cutlass and acceptable tolerance is .010 from Teleflex. If the rubber inset of the bearing shows out of round or the driveshaft looks to be rubbing through one side, there is a huge amount of misalignment and that must be corrected.
TRD, I believe the vibration you encountered, unless you've had the boat weighted the same before without issue, would be prop cavitation.

[embo]

boatwakes, Or anyone,

3 quick ?s. Why would the prop turn easier in the water then out by hand? And if the boat is full of ballast, would that make the steering harder or should you still be able to "one finger it" in the turn?

Also, if my original steering cable is 17', would I be able to use a 19'? Reason I got a smoking deal on it and didn't realize my cable was only 17' till after I ordered it. It was recommended that I get a 19 by a few before I knew I actually had a 17'...that's how I got to this point.

[boatwakes]

Embo, the strut bearing is rubber and lubricated by water, thats why you should never put the boat in gear in the driveway. The water creats a cushion for the shaft to spin on and when it's dry, it doesn't spin very well.
If the boat is full of ballast, it should steer with the same torque. Often times, with the boat sitting at a harder angle and the prop blasting the rudder at that angle, people complain their steering is much harder. Thats only from the force of the water coming off the prop to the rudder. If the steering is fine at low speed with ballast then at full speed with ballast it should be the same, sub-planing speeds are when the steering can get tight. If steering is tight at slow speeds with ballast, then you're pinching the cable somewhere with your ballast. You probably could use a 19' if you've got area to run the extra cable without comprimising your steering, that's the only condition.

[embo]

Ok, that helps clarify things. Thank you for explaining it. I haven't ever put the boat in gear out of the water...didn't know about the strut bearing but also don't have a fake a lake either. But know I know for furture use if I ever get a fake a lake.

We will have to take the boat out with ballast here in the next couple of weeks and refresh our memories just how hard or easy it is to steer with ballast. I just remember it being difficult but then it might have during that "sub-planing" time period.

And thanks for the comment on the 19' cable.

Thanks to all who commented.

[embo]

Ok, I finally got home to take some pictures of the drive shaft exiting the bottom of the boat. Here they are:




I don't feel anything wrong when we operate the boat as far as vibrations or anything. Just wondering if this is a problem that should be attended to?

I can turn the prop with one hand pretty easily. I know I said I couldn't before very easily but I was wrong. Can't one finger it but using my hand it turns fine.

I don't have any leaks or anything indicating this is an issue but it's just out of center and my original question was does anyone else have this same situation and is this something that needs to be fixed? I have info telling me that some of the new boats come from the factory with their shafts not perfectly centered. If that is true than how much off center is too much?

[boatwakes]

That area is called the stern tube and is a "general" fit. The rule here is to make sure that: 1) the driveshaft is not touching anywhere externally on the stern tube and 2) your strut bearing is not out of round or your shaft seal in the boat is not leaking. If everything appears okay and you're not experiencing any drivebility issues, your golden.

[embo]

Ahh....that clears things up considerably. I will try to figure out then where the strut bearing, and shaft seal are located and check them. I got concerned when I saw this situation (pics above) and wanted to know if there was something wrong. Now, I am wanting to educate myself on these other two areas/items you mention for my own knowledge.

Like I said above too, nothing seems to be an issue just wanting to know more then if this "stern tube" is normal. Nothing seems to be touching that I can see.

Thank you boatwakes. If you had pics of where the strut bearing is or the shaft seal handy that would be nice to see them.

Thanks you guys for helping out.