Aquadrive installation

[RDW]

I have had a refit with a new Yanmar 57 horsepower engine and a new B-10 aquadrive. We went to Tortola with the Caribbean 1500. We later went to St. Martin. On the way we got a line around the prop. When we realized that we had a problem we stopped using the engine and sailed on. We used the engine for the last bit to get into the marina.
Upon inspecting everything we found grease had been released from the Aquadrive boot. Now we have various parties pointing fingers as to whether it was a proper installation. One party says the offset (out of alignment) should be greater than 12 degrees and the other says much less.
I will try to post pictures.
I would enjoy any advice.

[Alii]

The permissible angle on our AquaDrive is MUCH less than 12 degrees. We replaced engine mounts last year and tweeked and tweeked to achieve an equally-distributed compound angle of 3.5 degrees.

I have several different manuals on older models, not for a "new" B-12, so for what it's worth here's an overview:

"Max recommended joint angle is dependent on shaft speed ... The CV joints do not need to run at equal angles, but the effective lifetime is determined by the amount of the angle ... try to have as equal angle-distribution as possible."

There are tables and diagrams that illustrate how you measure 3-dimensionally and do the math to come up with "effective compound angle." At least for older models, the maximum compound angles permitted are:

20100-20380
0-2000 rpm = 8 degrees
2500 rpm = 6 degrees
3000 rpm = 5 degrees
4000 rpm = 4 degrees
5000 rpm = 3 degrees

Less is better, although you don't want zero. My BMW was replaced with a 50hp Yanmar in 1997, and the top-dollar yard in Connecticut screwed this up. Didn't catch up with us until 5 years later, on the other side of the planet. Now we carry a spare unit, swap out and rebuild every 5 years or so. The rebuild is NOT EASY, very messy and time-consuming, so best to hire a professional (against my general rule).

PM if you would like me to forward the documentation I have.

[Alii]

Mark Haller at Scandia Marine is an expert on AquaDrives -

Home

Very practical, friendly guy.

[RDW]

trying to post photos

[RDW]

more photos

[RDW]

The red tape in the first photo is what we put on to stop slinging grease.
The other photos show the unit and the grease that escaped.
The real question is does the installation correct. I have been told that the angle shown in the first picture is much too great.
sorry to be slow about getting good photos.
appreciate any help and previous post.
rdw

[Alii]

Ouch! This does not look right at all to me. Plus another factor is how far apart the joints are stretched. The first photo shows my 20100 AquaDrive from above, where the joints are nearly aligned and pulled apart maybe 2 inches. The second photo from the side shows where the "angle" was required in this installation. Even when you need to open the angle you should still try to keep the drives on the same longitudal line.

Tape will not save you. You'll need to rebuild or replace.

[Alii]

Problems with the original installation were probably exacerbated when the new engine mounts settled and compressed. After installing new mounts you must check and re-adjust your AquaDrive angles at 50 and 100 hours. It is also important to replace mounts after 5 years as Yanmar recommends -- otherwise your AquaDrive is the "weak link" at risk as your engine sags and rattles on the worn-out mounts.

Before replacing the AquaDrive (new or rebuilt) you'll need to resolve the core problem -- misalignment of the engine. The AquaDrive provides only some flexibility and leeway. I have heard tales of boatyards "selling" the AquaDrive in order to mask a poor, non-aligned installation. This needs to be thought out and addressed in three dimensions.

[Alii]

... And make sure the right mounts have been put in the right positions. At least with my 4JH2E there are 2 pairs of different mounts, designated for the port vs. starboard sides. The boatyard got this backwards on the original installation, causing the engine to settle lopsided.

[RDW]

No one else has any advice on aquadrive???
RDW

[jimbunyard]

Regardless of the specified angles, from the picture (though they can be misleading and induce perceived distortion), you appear to be at or near maximum travel, never a good static position in any mechanical system.

To compound the issue it appears that the drive and driven planes are mis-aligned (orange), as are the engine and propshaft axes. I'd say you need either to get a qualified mechanic to set the engine up correctly, or bone up on the procedure and do it yourself.

The advice given previously about rebuilding, checking engine mounts and re-aligning after run-in periods is all good...


Though it is notoriously difficult to make an accurate call from a single picture, I'd say it's an improper installation...

[dfelsent]

On a previous boat I had an aquadrive failure due to mis-alignment and hours. When I bought the boat grease had been slung. That was the one big thing the surveyor and I missed. Delivery interruptus resulted.

I didn't realize that misalignment was the root cause.

A few years later, I ended up replacing an engine mount, digging out the shaft strut and re-bedding it in proper alignment, moving and re-aligning the thrust bearing for the aquadrive and re-aligning the engine. While I was at it I took the shaft and flange to the local propeller shop (H&H, world class, lucky me.) They aligned the shaft flange and shaft as a unit.
None of this was that hard, just time consuming. The alignment of all of this required much patient thought.

The end result was a dramatic improvement in vibration and reduction in noise.

[Alii]

I've PM'd some documents to RDW showing how to measure the compound angles, pretty much as jimbunyard has illustrated. The documents were too large to upload here.

[stillbuilding]

Have an Aquadrive on a 2" sis shaft and Cummins 4BT.

I tried to get 3 degrees misalignment to allow correct functioning.

Seemed ok until the bolts attaching it to the transmission drive plate came adrift and needed remachining. The whole thing was hanging by one bolt - just lucky I found it.

There is no service agent in Australia and the competent person in NZ couldn't go out his way to provide the local engineer with accurate drawings so had to do it on the fly.

Nice when it's working but make sure you have replacement bolts.

[Alii]

Mark Haller at Scandia Marina in Singapore is very knowledgeable, and provided me with drawings and documents not available elsewhere (except I believe directly from GKN Driveline, as the manufacturer in Sweden is now known). Some time ago Aqualine was acquired by the German conglomerate GKN that produces CV-joints, etc. for many major automotive manufacturers. At the time of the acquisition there was a reshuffling of AquaDrive products and some models (like mine) were dropped from production.

Other than the blown seals caused by the original, improper installation, I have had no problems with my AquaDrives -- now swapping out and rebuilding the units every 5 years when new engine mounts go in. That's 13 years and at least 7000 hours of reliable service.