Re: Bow Thruster Service


Mike Ondra
 

Here’s another twist on bow thruster service.

We services ours yesterday, on the hard, so no extra complications from doing it in the water. Last service less than a year ago was in the water, and we were not confident that the reinstall was completely waterproof. Indeed, it was not, and we had our share of oil and cream.

Anyway after removing the 4 bolts that hold the GRP shaft, the motor housing spun freely on the GRP, but the thruster would not drop. We surmised that the splined connection between the motor shaft and thruster drive shaft had seized. No amount of tugging from below would move it. Ultimately we lowered the bow thruster and from below lifted it a few inches and “bumped” it with a short drop, well maybe a little bit more than a short drop to get results.

Anyway, the lesson is to lubricate the splined connection when reassembling the bow thruster to prevent seizing. We used Molykote.

Mike & Tom

ALETES SM#240

Chesapeake Bay

From: main@AmelYachtOwners.groups.io <main@AmelYachtOwners.groups.io> On Behalf Of Matt Salatino via Groups.Io
Sent: Wednesday, August 28, 2019 2:53 PM
To: main@amelyachtowners.groups.io
Subject: Re: [AmelYachtOwners] Bow Thruster Service

 

Good to know

~~~⛵️~~~Matt


On Aug 28, 2019, at 11:45 AM, CW Bill Rouse <brouse@...> wrote:

Mat,

 

It depends on how much heat is applied and you can certainly damage GRP with a heat gun. This is the reason I would never say to carefully use a heat gun, nor would I say enough heat.  "Carefully" or "enough" are non-specific. For instance, enough heat to separate, might be enough heat to damage GRP.

 

Best,

 

CW Bill Rouse

720 Winnie St

Galveston Island, TX 77550

+1(832) 380-4970

Image removed by sender.

 

 

On Wed, Aug 28, 2019 at 1:33 PM Matt Salatino via Groups.Io <helmsmatt=yahoo.com@groups.io> wrote:

Bill,

Would a heatgun provide enoughheat without affecting the FRP?

~~~⛵️~~~Matt


On Aug 28, 2019, at 10:21 AM, CW Bill Rouse <brouse@...> wrote:

Bernd,

 

You should be very, very careful with heat because the Bow Thruster Tube and case is made of GRP, not metal. 

 

The contact point is Cast Iron to the GRP tube. The problem is a result of NOT replacing the lip-seal and foam donuts, and possibly leaving the bow thruster down while sailing or motoring. Saltwater has passed through the seals and has caused corrosion on the electric motor base which is made of Cast Iron. This corrosion (Iron Oxidation) has reduced the size of the opening for the tube at the base of the motor. Your photos show that this has been more than a little saltwater over a long time, possibly months/years. It is going to be very difficult to separate the tube from the motor base. You will need the tool designed by Amel, plenty of penetrating fluid and 3-4 days of constant pressure to cause separation. You can use some light tapping or vibration on the cast iron motor base intermittently while constant pressure is applied with the special tool. But take care not to strile the base too hard because it is made of cast iron.

 

<image.png>

I recommend that you closely check the lower bearing on the electric motor because I suspect it is also damaged.

 

In the future, replace the seals every 2 years...also replace the 0.3 liters of 80/90 Gear Oil when you replace the seals. Always use plenty of waterproof grease at the contact points of the tube and motor base.

 

This is the normal materials needed for service every 2 years (contact SAV"at"Amel.fr):

<image.png>

You will certainly get other advice, but I firmly believe that you will not get better advice.

 

Best,

 

CW Bill Rouse

720 Winnie St

Galveston Island, TX 77550

+1(832) 380-4970

Image removed by sender.

 

 

On Wed, Aug 28, 2019 at 12:03 PM Matt Salatino via Groups.Io <helmsmatt=yahoo.com@groups.io> wrote:

A little heat?

~~~⛵️~~~Matt


On Aug 28, 2019, at 9:44 AM, "jlm@..." <jlm@...> wrote:

Hi !

I had the  same problem ... You need a lot of patience, mutch WD40 and patience, do not forcing, do not break the threads, the contact is bronze on stainless  ...

I needed 2 days ...

good luck

JLM

CottonBay


Hold time 2 or 3 days with WD40, WD40 and much

Le 28/08/2019 à 18:35, Bernd Spanner a écrit :

Hello,
I wanted to change the seal on the bow thruster today.
Unforunately after removing the 4 screws I could not get the shaft disconnected. It’s badly rusted all over. Any ideas how I can loosen it?? Already used some wd40 & caramba to get it loose.... no success 
Pics attached
Best regards, 
Bernd
SN 119 / Cascais, Portugal

 

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