Replacing C Drive mounts while boat is in the water.


Paul Guenette
 

We are about to replace the engine mounts, change the rubber bushings on the Vetus Coupling  and hopefully change the C-Drive mounts on our Super Maramu.

I have searched thIs amazing forum and I have read Bill's book. I have found a lot of really good helpful information on replacing the engine mounts on our Yanmar 4JH3-HTE and how to approach servicing the Vetus Coupling. 

Here is the only information regarding the C-Drive that I have been able to find up till now. 

"It is possible that the new position will put in tension the C-Drive Rubber Hose which seals the opening between the C-Drive and the hull (see above photo).    
 (I have not include the photo in this post) 
Loosen the top two large hose clamps to place the hose clamps to place the hose in a neutral stress-free position.
CAUTION
During this operation, the sea water will enter the boat but the gray water sump is nearby. Tighten the two clamps when complete."

What I am looking for is information on and the steps involved in replacing the two C-Drive mounts. I have on hand two new mounts which are the same as the current ones installed on my C Drive.

Our boat is in the water.  Is it okay to replace the C Drive mounts while in the water ?  

What are the steps involved in replacing the two C-Drive mounts and any helpful tips from those who have done this procedure ?

The information and knowledge base in this forum has been extremely helpful. 

Thank you for your help. 

Paul
Aramis  SM 2K - 444
Comox, BC Canada


Alex BAIZEAU
 

I don't have an answer to your question but I was in comox on NYE - what a nice little town
image.png

On Wed, Jan 13, 2021 at 10:47 AM Paul Guenette via groups.io <paulguenette=icloud.com@groups.io> wrote:
We are about to replace the engine mounts, change the rubber bushings on the Vetus Coupling  and hopefully change the C-Drive mounts on our Super Maramu.

I have searched thIs amazing forum and I have read Bill's book. I have found a lot of really good helpful information on replacing the engine mounts on our Yanmar 4JH3-HTE and how to approach servicing the Vetus Coupling. 

Here is the only information regarding the C-Drive that I have been able to find up till now. 

"It is possible that the new position will put in tension the C-Drive Rubber Hose which seals the opening between the C-Drive and the hull (see above photo).    
 (I have not include the photo in this post) 
Loosen the top two large hose clamps to place the hose clamps to place the hose in a neutral stress-free position.
CAUTION
During this operation, the sea water will enter the boat but the gray water sump is nearby. Tighten the two clamps when complete."

What I am looking for is information on and the steps involved in replacing the two C-Drive mounts. I have on hand two new mounts which are the same as the current ones installed on my C Drive.

Our boat is in the water.  Is it okay to replace the C Drive mounts while in the water ?  

What are the steps involved in replacing the two C-Drive mounts and any helpful tips from those who have done this procedure ?

The information and knowledge base in this forum has been extremely helpful. 

Thank you for your help. 

Paul
Aramis  SM 2K - 444
Comox, BC Canada


Paul Guenette
 

I just found this post from Mark McGovern, posted 10/07/18, with information from Oliver Beaute

The part that refers to the C-Drive mounts I have made the text BOLD.
It looks like  Mark posted pictures to the old Yahoo site but I have not been able to locate them yet on this site. 

https://amelyachtowners.groups.io/g/main/topic/29770137#42506


10/07/18   

Hello Mark,

 

this is something you probably can do, considering your "automotive" background.

 

The main thing is to be meticulous.

 

First about your questions:

-You don't absolutely need to replace the VETUS coupling if it is in good 

condition:

       -the steel rods that hold the rubber "donuts" must not have moved from the 

steel hub, if so, replace the coupling

       -the holes for the bolts should not be damaged (ovalized), otherwise, replace 

the coupling

However, you will probably need to replace the donuts, easy to buy from VETUS.

 

If you need to replace the whole VETUS coupling, it is a standard coupling from VETUS, for a 35mm diameter shaft, with a key way for the C-drive input shaft BUT AMEL has the aluminium part machined in order it  "enters" the gear-box flange. You will see this when the gear-box is disconnected from the coupling (and if you compare with your new VETUS coupling).

 

Before touching the tools, make pictures and take notes (measurements of all the fittings, position of the nuts on the rubber mounts, position of the engine on the steel cradle, position of the shaft brake disc, etc...).

 

Start with disconnecting the hoses that could prevent you from moving the engine backwards on its cradle.

 

Then undo the coupling bolts and the engine steel supports' bolts (attaching the engine on the steel cradle).

 

Then move the engine backwards enough to remove the coupling bolts.

 

Undo the C-drive bolts of its rubber mounts. 

 

Remove these mounts. 

 

The C-drive will be held by the big rubber sleeve at the bottom.

Lift the engine just enough to be able to lift the cradle and remove and replace the YANMAR mounts with their lower nut set approximately like the previous ones were.

Re-install the C-drive mounts.

Then comes the alignment process.

 

AMEL uses a tool which is a steel coupling machined so that its aft side "enters" the gear-box flange (see pictures and drawing). You can also pre-install the new coupling and adjust the position of the mounts.

 

First bring the engine forward and make sure the coupling is centered with the gear-box flange, and can enter the gap in the flange. 

 

Then move the engine a little bit backwards and check that the gap between the flange and the aft side of the coupler is even all around the circumference. To adjust this, you need "thickness wedges" (used in the automotive industry) and play with the rubber mounts nuts to make the gap even.

 

Then bring the engine forward and tighten the bolts on the cradle and on the mounts.

 

The advantage of using the tool AMEL uses is that it is easier to install while checking the gaps.

If you need to make one, here's a drawing of the alignment tool for a YANMAR 4JH3-HTE.

The inside diameter (C-drive input shaft) is 35 mm.

The outside diameter is 100 mm.

The diameter of the part that enters the gear-box flange cylindric gap is 62.8 mm, thickness 3 mm.

 

You should use a VETUS fixed coupling for 35mm shafts, then have it machined to make the 62.8mm "plug" and drilled for the four bolts that should match the flange holes.

 

I think AMEL still sells the VETUS machined coupling, you will ask Maud when she's back from holidays.

 

Hope this is clear enough.

 

Best regards.

 

Olivier BEAUTE / ATLANTIC YACHT SURVEY

10 allée du Bout dehors

17000 LA ROCHELLE

Tel: +33 546 522 147   Mob: +33 674 028 243

 http://atlanticyachtsurvey.com

 

Now you see why I recommend Olivier to everyone. 

Hope this helps you. 

Mark McGovern 

SM 440 Cara

Deale, MD USA


Craig Briggs
 

Hi Paul,
It's been a while but as I recall you can disassemble the frame members around the "C" drive upper and then easily slip in the new mounts. The "C" drive is happy to sit by itself on its "trumpet" and the big rubber hose while you do this. Then adjust the mounts to "share the load" with the trumpet and retain alignment with the transmission output shaft. You could loosen the clamps on the hose to be sure it seats happily, but will likely be back in exactly the same orientation. Can certainly be done in the water.
Good fun, 
Craig,
SN68 Sangaris, Tropic Isle Harbor, FL


Mark McGovern
 
Edited

Paul,

Changing the C-Drive mounts is quite straightforward and pretty much exactly as Craig describes.  See the picture below:



Remove the nuts circled in Red above from the mounting studs. Then remove the mounting stud from each C-Drive mount.  Then remove the bolts circled in Yellow that bolt the C-drive mount to the engine mounting frame.  Once you do that you can slide the old C-Drive mounts out from under the mounting frame and slide the new ones in.  As I understand it, the mounts should be adjusted so they are just barely starting to support the weight of C-Drive.  If you crank them up too much you will put strain on the rubber hose that is keeping the water out of the boat.  To relieve any strain, you can loosen the top two hose clamps on the large rubber hose (water will come in) and then tighten them back up.  

All of the documents that I uploaded to the old Yahoo forums were transferred here when we moved off Yahoo so they are here somewhere.  In order to make it easier to find, I just created a new Photo Album called Engine to C-Drive Alignment here:  https://amelyachtowners.groups.io/g/main/album?id=259361 


--
Mark McGovern
SM #440 Cara
Deale, MD USA


eric freedman
 

The Vetus coupling shown in those photos is the one from Vetus. It is not the one that is mounted on the Amel’s. Amel machines the coupling shown in the photo to fit their engines. The one in the photo will not work. You need to get the correct one only from Amel.

Fair Winds

Eric

Kimberlite Amel Super Maramu #376

 

 

From: main@AmelYachtOwners.groups.io [mailto:main@AmelYachtOwners.groups.io] On Behalf Of Mark McGovern
Sent: Wednesday, January 13, 2021 10:42 PM
To: main@AmelYachtOwners.groups.io
Subject: Re: [AmelYachtOwners] Replacing C Drive mounts while boat is in the water.

 

Paul,

Changing the C-Drive mounts is quite straightforward and pretty much exactly as Craig describes.  See the picture below:



Remove the nuts circled in Red above from the mounting studs. Then remove the mounting stud from each C-Drive mount.  Then remove the bolts circled in Yellow that bolt the C-drive mount to the engine mounting frame.  Once you do that you can slide the old C-Drive mounts out from under the mounting frame and slide the new ones in.  As I understand it, the mounts should be adjusted so they are just barely starting to support the weight of C-Drive.  If you crank them up too much you will put strain on the rubber hose that is keeping the water out of the boat.  To relieve any strain, you can loosen the top two hose clamps on the large rubber hose (water will come in) and they tighten them back up.  

All of the documents that I uploaded to the old Yahoo forums were transferred here when we moved off Yahoo so they are here somewhere.  In order to make it easier to find, I just created a new Photo Album called Engine to C-Drive Alignment here:  https://amelyachtowners.groups.io/g/main/album?id=259361 


--
Mark McGovern
SM #440 Cara
Deale, MD USA


Ian Park
 
Edited

Craig forgot to mention that there is a ring fixed directly above the C Drive (he told me that) which is there to lift the C Drive or take its weight should you need to do so. You may have to dig around in the soundproofing to find it. I have just finished checking my mountings and realigning everything. I found a few photos of Craig removing the C Drive from the boat and one showed how he put a rope round the C Drive cross beam to hoist it.  you may feel more comfortable taking the weight off the C Drive mounting using this system.
Ian
Ocean Hobo SN 96

PS. To Craig. Thanks for all your help this summer about realignment.. I got home and bought a chain lift to have a proper go at the job. I had the Amel tool made, but on my Santorin the shaft coupling worked equally well. The coupling systems seem to be different on some of the SMs, especially with the shaft brake. One thing I found when double checking the alignment, was to reassemble the shaft coupling and Vetus coupling  with shorter (4" ) bolts. I could then slide the whole assembly on the drive shaft, across the empty space where the alternator pulley would normally be and found the ends of the Vetus  bolts slide neatly into the gearbox holes.


Craig Briggs
 

Hi Ian - glad it all worked out and appreciate the feedback. 
Craig
--
SN68 Sangaris, Tropic Isle Harbor, FL


Paul Guenette
 
Edited

Thank you  Craig, Mark, Eric and Ian   (and Alex).  I really appreciate your help.

I also have the extra alternator for generating power while under sail.  It looks like I can remove it as one unit by undoing the two bolts that attach its framework to the C-Drive cross frame/beam.






Paul Guenette
 

Thank you Ian,

I checked and I have not been able to see or find that ring, (I will dig a little deeper).

Paul Guenette
Aramis
SM - 444
Comox, BC Canada