Aquadrive System

Greetings Guys

As my boat is being built from scratch, I was recently recommended to install an Aquadrive Transmission System. They claim to generate zero vibration and a reduction of a substantial amount of sound when properly installed.
The problem is that I haven’t seen one system installed yet. (Aquadrive)

Have any of you guys seen this thing in action?

Regards

Fernando

Been on board a 55 Fleming with Aquadrive and it really works.

I know Fernando that every which way you turn there is another $5K gadget that one would like to add to your list of wants and/or must-haves but on this one I believe you will reap an unseen reward if you do. If I were building my boat from scratch I would install anything that would make my boating experience a pleasure.

I wish I had one in my boat to give you a 'without' and a 'with' first hand comparison but I can't..

Elwin

ancora said:

Been on board a 55 Fleming with Aquadrive and it really works.

Click to expand...

so does a well mounted egine, good isolation mounts and good alignment....

I installed an AD in my last boat and it Didn't eliminate all the vibration but I highly recomend it and if money was no object they should be in all boats. The best way to do it and the only responsible way to do it if you have really soft mounts ................ And that's the usual way to low vibration. The whole drive system should last much longer w AD or Python Drive.

Oh ..... Check out Evolution Drive too.

Don't have them but have talked to boat owners who do in boats ranging from 36' to 50-something. All have said that they work as advertised. The big advantage is that an Aquadrive (or one of the other similar units) allows you to switch to much softer engine mounts which is what reduces the vibration. If you install an Aquadrve but retain the stock hard mounts-- necessary to maintain alignment with a rigid shaft coupling-- there is apparently little to no reduction in vibration. The key is to install an Aquadive and softer engine mounts.

And of course you can't install the softer mounts without installing an Aquadrive, too, since the soft mounts won't maintain proper shaft alignment with a rigid coupler.

OK Guys

Based on your opinions and in the fact that a retired couple and precious expensive equipment can appreciate a quite ride, I went crazy and bought a fit for purpose Aquadrive Transmission system.
I am well aware that quality is never expensive but can eventually be priceless. Depends on where resides the concept of value. For me, one of the measures of value can be a quite boat, with low levels of noise and vibration.
Having now a transmission system of this nature, I need to install a softer set of engine mounts to disperse vibration which will die in my Transmission system, I hope!!!
Be certain that I will be reporting the results when time comes.
Regards

Fernando-we have the AD in a twin JD installation and one big point not previously mentioned is shaft alignment. The alignment is shaft to AD, not to engine and is way, way easier and is virtually a "do it once" operation. No need for checking or adjustment on shaft alignment.

Good luck with it!

Portuguese said:

OK Guys

Based on your opinions and in the fact that a retired couple and precious expensive equipment can appreciate a quite ride, I went crazy and bought a fit for purpose Aquadrive Transmission system.
I am well aware that quality is never expensive but can eventually be priceless. Depends on where resides the concept of value. For me, one of the measures of value can be a quite boat, with low levels of noise and vibration.
Having now a transmission system of this nature, I need to install a softer set of engine mounts to disperse vibration which will die in my Transmission system, I hope!!!
Be certain that I will be reporting the results when time comes.
Regards

Click to expand...

Did you se this thread on the system you are talking about?

http://www.trawlerforum.com/forums/s3/clunk-aaahh-crunch-6302-2.html#post89550

Aquadrive systems use a CV type of u-joint, not the type of open u-joint in Mark Pierce's boat.

See Aquadrive

Larry H said:

Aquadrive systems use a CV type of u-joint, not the type of open u-joint in Mark Pierce's boat.

See Aquadrive

Click to expand...

good to know...on cars if the boot tears the cv joint is soon doomed...is the same true with the Aquadrive system? How well are the cv joints mainized/protected?

Aquadrive is one of those things that stay on my wish-list, but I can't quite get down the list that far yet. I have a relatively quiet boat. The Yanmar refit, cored hull and two decks of separation make sound and vibration almost undetectable from the pilothouse. Still, the vibes down below could be less, and I've never met anyone with an Aquadrive that wasn't happy with it. I'll probably install one before we go full time cruising in 2014. The Admiral supports anything that makes the boat quieter, but along with the Aquadrive, I will also want to have the engine-room video monitors installed. I want a quiet boat, but I'm a bit fearful that I'll become too insulated from the driveline.

Many unnecessary moving parts , many more potential problems , shalt must be aligned to thrust bearing and kept within tight tolerance just like with engine or more so because thrust bearing has little or no give, temperature must be monitors or check regularly, not enough benefit for potential problems ,I will not make that mistake again after expensive problems and much lost cruising time. That is my experience with Aquadrive. Good luck,

rking said:

Many unnecessary moving parts , many more potential problems , shalt must be aligned to thrust bearing and kept within tight tolerance just like with engine or more so because thrust bearing has little or no give, temperature must be monitors or check regularly, not enough benefit for potential problems ,I will not make that mistake again after expensive problems and much lost cruising time. That is my experience with Aquadrive. Good luck,

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Old thread I know, but what problems did you have. I'm seriously considering putting this system on my twins.

Quiet alone would be worth the added expense ,

BUT in the future you will NEVER have to align the shaft !

If you keep the boat long enough replacing the engine is a snap if about the same HP.

WE love ours , although learned the hard way some shaft mis alignment is REQUIRED!

My biggest problem was getting the thrust bearing aligned and positioned. I had the "baby AD" w only two ears and thus mounting bolts. Got my epoxied in plywood thrust bearing mount slightly off pitch wise. I had to use big washers ground so they were thinner on one side. To finally arrive at the perfect angle pitch wise was a lot of extra work.

Most all (or all) the other thrust bearings had 4 ears and could be easily adjusted for pitch. Avoid the two eared models if there is any now.

The other "problem" is that I did it to solve a harmonic vibration problem and the vibration was still there when I sold the boat ... to a wonderful and interesting engineer (female) for Washington State ferries. I don't think it bothered her.

The vibration went like this .. rum ..... rum .... rum like a twin engine boat w engines very slightly out of sync. I had Norm Dibble (well known and very experienced boat engine mechanic (some of you may remember him)) and he was basically baffled. He finally concluded it was the hull bottom vibrating but why and how that was happening he, I and we never did resolve.

The above is the source of my experience that promps me to say the AD may not solve your vibration problems. About once a year I still wonder what it was.

The AD never gave any trouble as we went to Alaska an back without a hitch but listening to the light drumming vibration all the way.

manyboats said:

My biggest problem was getting the thrust bearing aligned and positioned. I had the "baby AD" w only two ears and thus mounting bolts. Got my epoxied in plywood thrust bearing mount slightly off pitch wise. I had to use big washers ground so they were thinner on one side. To finally arrive at the perfect angle pitch wise was a lot of extra work.

Most all (or all) the other thrust bearings had 4 ears and could be easily adjusted for pitch. Avoid the two eared models if there is any now.

The other "problem" is that I did it to solve a harmonic vibration problem and the vibration was still there when I sold the boat ... to a wonderful and interesting engineer (female) for Washington State ferries. I don't think it bothered her.

The vibration went like this .. rum ..... rum .... rum like a twin engine boat w engines very slightly out of sync. I had Norm Dibble (well known and very experienced boat engine mechanic (some of you may remember him)) and he was basically baffled. He finally concluded it was the hull bottom vibrating but why and how that was happening he, I and we never did resolve.

The above is the source of my experience that promps me to say the AD may not solve your vibration problems. About once a year I still wonder what it was.

The AD never gave any trouble as we went to Alaska an back without a hitch but listening to the light drumming vibration all the way.

Click to expand...

I think you might be right Eric - some vibrations will forever be a mystery. I had one of the original design engineers for the CAT 3306 on Delfin, as I have a thrumming when I rev up over around 1500 rpm. Not much of a problem since I only do so to blow her out after cruising at 1350 for a day but I wanted his advice on what I could do. He told me that the engine was designed for the North Slope and they needed an engine that would not goo up when idled during freezing weather for long periods of time. He said they made the oil channels oversized and that created an echo chamber inside the engine that was going to resonate as certain rpms whatever you did. Kind of like trying to quiet the orchestra by putting the stage on soft mounts.

Still, the AD is intriguing and I wonder if bigger prop sizes would make it more effective?

I have owned two boats with aquadrive SX. My present custom boat does not have it and does not really miss it. The early pilgrim 40 I owned came without and had a lot of vibration and noise we retrofitted AD and it was a big improvement. All future pilgrims had AD as standard rig. The True North 38 came with AD and at low speed it vibrated but was fine above 1200 rpm. So it all depends on boat and how motor is mounted. Why not build boat without but allow for easy retrofit if needed. This means a place to have the thrust bearing plate and enough room for the AD along the shaft then the a retrofit would be easy cut shaft bolt to thrust bearing plates and off you go.

What is different about the Aguadrive, compared to regular transmissions?

Aquadrive is a constant velocity joint combined with a thrust bearing. It is installed after a regular transmission. Regular in-board setups have the transmission output flange connected directly to the shaft flange. Alignment issues are transmitted to the rest of the boat. In other words with AD the shaft is held stationary and the engine and transmission are allowed to move (via the CV joint) without affecting the rest of the drive train.

On my boat the CV joint is a VW part.

Super-in a traditional setup- engine connects to tranny, tranny to prop haft. the drive energy from the prop is transmitted to the tranny and thus to the engine. In essence, the propulsive force of the prop is transmitted tot he hull through the engine mounts. The alignment has to be almost perfect and any movement by any piece of the drive train will cause vibration or damage to the drive train. With AQ, a thrust bearing is mounted on a plate attached to structural hull members (stringers). The thrust bearing absorbs the propulsive force of prop. The prop shaft is aligned with the thrust bearing plate. Since the bearing plate is hard mounted, that alignment only needs to be done once and there is no movement to upset the alignment. The engine/tranny is attached to the thrust bearing via a CV joint. This allows some freedom in engine mounting as it need not be in a direct line to the prop shaft. It also allows the use of very soft engine mounts as engine movement is no longer an issue with the CV joint. This eliminates or greatly reduces any engine vibration. The engine/tranny are isolated from the prop shaft. All propulsive force is absorbed by and transmitted to the hull be the thrust bearing and plate.

Well said Salty Dog and THD.

Every boat should have one but the effects of not having one cannot be felt on many installations.

One can make a strong case for saying they are or should be required for any engine installation that has flexible mounts. Less so when the mounts are stiff or very stiff. It's insane or at least stupid to have quite to very flexible engine mounts and no Aqua Drive Or equivalent. When an engine moves in the yaw or pitch axis extreme forces must be present at the thrust bearing in the transmission, coupling and fwd end of the prop shaft. If the TX bearing, coupling and shaft are strong enough then the shaft would prevent the engine from moving in the yaw and pitch axis. Doubt if that could ever happen.

If the propeller shaft is in line w the center of rotation of the engine when subject to torsional movement the movement would be only in accelerating and decelerating the rotational movement of the shaft. Propeller blade tips would accelerate and decelerate slightly but the shaft would not move up or down. But almost always the shaft is well below the rotational center so torsional vibration will move the shaft back and forth from side to side. Nothing but an Aqua Drive can absorb those movements gracefully.

Any way you stack this up the standard straight shaft drive w flexible engine mounts is an undesirable way to transmit power to the prop in a small boat. My boat falls into this category but it's plenty smooth enough to keep using the straight drive.

If the shaft gland has some room to accomodate some motion of the shaft, then the normal vibes of the engine do not cause alignment problems. Even soft mounts designed for propusion engines do not displace very much under load. Most shaft lines can handle that displacement without issue.

Also, some vibration energy from the prop comes up the shaft, but is absorbed by the mass of the engine on the soft mounts. Solid mount a thrust bearing to the hull with aquadrive, and vibes coming up the shaft get right into the hull.

If the shaft has a cutless bearing where it comes through the hull, or a solid mounted packing gland, then the motion of the engine on soft mounts can really cause trouble. Aquadrive et al are very handy there. But those installs are pretty rare in trawler type boats.

These types of thrust bearings and drives have their uses, and do well there. But they are not the be-all, end-all type of fix for vibration and noise issues.

Folks that install a set with more flexible mounts MUST look at all the other items , that attach to the engine , like the water inlet and exhaust and perhaps re doo them to handle the new engine motion.

Its the complete power system that is being revamped.

FF is correct.
When motor mounts are flexible enough, everything else attached to the motor must follow that flexibility or, pay the price!

FF is correct as usual,
I agree. And I personally have a stone to uncover on Willy in that regard. Willy has a tall exhaust riser connected to a FG lift muffler via a very stiff exhaust hose. I haven't brought it to the fore yet as I have little vibration and so many other priorities.

Anyway the engine vibration will be greatest on the attached parts furthest away from the center of rotational/torsional vibration. The attach point of the hose is such a point but can hardly move. I think I need to attach a flexible short pipe (accordion) of SS to allow the engine to move.

And of course there is that possibility that that rigid hose is keeping the engine from moving and reducing vibration. But one would think that would just transfer the vibration to the lift muffler or what it is mounted to.

My engine mounts are fairly rigid. Polly Flex plastic. So this thread is a reminder to get w the yard guys and "get-er-done".

I've decided to go with the Aquadrive (s). I met with the mechanic yesterday and we're going to finalize the modifications in about 3 weeks . Aquadrive says the system can handle 15 degrees of misalignment but prefer 10 or less. I've calculated that I can lower the front of the engine about 3.5" and end up at 9 degrees. This will give me the ability to take off the rocker cover to adjust valves, service injectors, etc; which is impossible now.

We will move the engines 2 " forward as well to give the space needed for the Aquadrive and access to the stuffing box for repacking.

Again, all this is subject to many double checks. If every thing works out the work will be done in September. Still time to do sea trials before haul out for winter up here in Ontariario.

At least, those are the plans for the moment.

Sounds like it will fix a lot of issues for you. Which model of Aquadrive are they recommending for the twin Lehman 120's.

I just finished my installation on a 42ft steel hull and I can say vibration have been reduced by 80%. The engine does not shake at all unlike before the AD. The motor is barely felt when running. Please remember I have a steel boat and I now have 76 inch of free float shaft that is not shaking the hull.

As I recall the ideal (and necessary) misalignment is 2 degrees.

I wouldn't consider much more than 3 degrees.

Perfect alignment is to be avoided. A slight misalignment is necessary to cycle or rotate the CV joint parts so they won't stay in one position and wear prematurely.