Thanks so much for the info, which is critical.

That is absolutely crazy a company such as ZF could make such mistake and not (really) address it for so many years…
All manufacturers should have been warn about that with the proper dipstick sent…

Alexandre

--------------------------------------------
On Tue, 7/24/18, trifin@... [amelyachtowners] <amelyachtowners@...> wrote:

Subject: [Amel Yacht Owners] ZF25 Transmission Dipstick / Fluid Level
To: amelyachtowners@...
Date: Tuesday, July 24, 2018, 6:38 AM


 









IMPORTANT NOTICE
To all Amel Owners,
I have recently had a failure event with
my ZF25 gearbox. You can read about it further in Topic
#41215 on this forum.  In that failure event, the dipstick
for my ZF25 was damaged, and so I needed some means of
checking fluid level until a new dipstick was
delivered.
I then embarked on
a very confusing 2 week journey of trying to determine
independently where the correct fluid level should be in a
ZF25 gearbox without reference to a dipstick. The results of
this are very significant for Amel owners with ZF25
gearboxes.
Please note the
following:
1. ZF Marine have
informed me that ALL user manuals, parts lists, service
manuals, brochures, marketing specs, website data etc for
the ZF25 gearbox which state that the fluid capacity of the
gearbox is 2.0Litres, are all incorrect.  
2. The correct fluid level for the ZF25
gearbox is 3.0L, but this figure only appears in the
original installation drawing of the ZF25 (in Italian),
which ZF sent to me and I will post on the forum files
archive.  
3. Some owners
will already suspect that it is really a 3L box because they
will add 2.0L as specified in the manual, and then wonder
why they needed to add another full litre to bring it up to
the top of their dipstick. These owners have a
"short" dipstick and can rest easy.
4. However, some owners will add 2.0l
and find that its already close to the full mark on their
dipstick.  If you are one of those owners then this message
is addressed to you.
5. I know
that some Amel 54 models have been supplied with an
incorrect dipstick.  This dipstick is too long and reads
"full" when 2 litres of fluid is present in the
gearbox. These boats have been operating one litre short of
fluid, which equates to a fluid level which is about 20mm
too low.
7. I do not know who
made the change of dipstick in the production process of
these boats, but I can guess why they made the change, that
is to try and match the disptick to the 2litre capacity
widely published by ZF.
I urge
all owners to check your dipstick against the following
information:
If you have a
dipstick with part numbers
3312-301-028 or 3312-201-002 
then you have the wrong dipstick and
your ZF25 is at risk of damage due to low fluid
level.
If you have a dipstick
with part numbers 
3311-301-003 or 3311-201-001
then you have the correct dipstick and
you will have the correct 3.0l of fluid in your
gearbox.
If you have already
experienced the failure and have replaced your gearbox with
a new one from ZF, then you will most likely have the
correct dipstick. 
Finally,
as an absolute measure, the correct fluid level is between
84.5mm and 96.5mm from the mating face of the dipstick
hole. 
I do not know if this
problem ever affected SM production, but I do know that the
documentation error from ZF was present in 2002. 
I am collating a private list of hull
numbers which have been affected by this issue, and I would
really appreciate if owners would email me privately on the
email belowor simply post here on the
forum.
I'd like to know
your hull number and :1. whether you have the long
(incorrect) dipstick and if you've had transmission
troubles,2. If you have the short (correct) dipstick,
have you renewed your transmission (or dipstick) since the
the boat was delivered new.

Thank
youDr Dean GilliesSY STELLAAMEL 54
#154+61 411 967106trifin (at) soundthinking
(dot) com (dot) au

 

Hi Alexandre,

Yes its interesting.  

I dont know who changed the dipsticks. Personally I don't believe ZF shipped the wrong ones, I think they were changed by someone to try and match the ZF published capacity of 2Litres.

If you use the correct dipstick, you might wonder about the extra fluid needed, but you will always end up with 3l because you use the dipstick as the master reference.

Cheers
Dean

 

On 24 July 2018 at 22:08 "trifin@... [amelyachtowners]" <amelyachtowners@...> wrote:

 

 

Hi All,

After load testing this morning I am 99% sure my ZF25 transmission has failed.  

I know the root cause of the failure, and I will publish separately on that issue later.

I'm told by the ZF representatives that a new transmission will take at least 3 months to supply.  

I don't want to entertain re-conditioning of this box because I know the root cause of the problem.

Our sailing season is over before it started, the admiral is devastated and has lost all confidence in the boat.  We will most likely winterise the boat and go home soon. 

 

However, before I do that I'd like to convert that 99% to 100%, to be absolutely certain that the problem is the gearbox.  I'm finding it difficult to get the required level of professional support here in Kalamata, so I'm hoping for some sage guidance from the group. 

So, the symptoms...

Two weeks ago we started motoring due to no wind. Flat sea, running about 1700-1800rpm.

I started hearing some "modulation" of the engine tone, like wandering RPM. 

I also noticed the disappearance of a "rattle/chatter" sound which has always come from our Morse Control.  It's not a loud rattle, but is clearly transmitted from the gearbox up the gearshift cable and resonates from the hand control unit. (Is that a standard thing - or an early symptom of a gearbox problem?)

I thought we had something stuck on the propeller, so we stopped and I checked it. Nothing.

We started again and the boat would not run up to normal speeds for the RPM we were using.

We stopped again, and I checked the engine room once more. Fluids ok, no leaks, nothing looked out of the ordinary.  So  we continued and I increased the RPM to about 2000-2100, and continued on making only about 4 knots.

After 10 minutes or so, I opened the engine room again to check, and was met with an outburst of smoke, burning smell and everything was very hot.  After stopping and investigating further I found the cause of the overheat was that the shaft brake was stuck closed.  The ZF 25 gearbox was also very hot, and when I opened it to check the fluid again the lower part of the dipstick was melted into an elongated blob of plastic.   

There was no fluid leakage, so I assumed that the fluid  level was still ok. 

I found out how to undo the shaft brake, and wedged a spanner in it to make sure it stayed open. By then everything was cooled down and we proceeded to motor slowly to shore at about 1200rpm. Interestingly the "rattle" mentioned above was back.

We flushed and changed fluids and ran the boat gently for a day or two until we got to a marina.  

On testing the boat, we find that all is well until we exceed 2000rpm. Quite quickly after running at 2100rpm our little rattle stops, then the engine noise starts to waver and sounds like it it reducing in rpm, although the digital readout of rpm does not change from 2100rpm. The boat then starts to slow down from the 8.3 knots it was travelling at with 2000rpm. It drops a couple of knots.  On checking the shaft brake at this point it is still open so that is not the reason for slowing.  If I increase the engine power, we get no more thrust from the propeller.

After this happens, I struggle to generate thrust even at lower rpm.  Leaving everything to cool down completely appears to reset the problem. The rattle comes back, low RPM operation is ok, but when loaded up the gearbox seems to be failing.

The one thing which is niggling in my head is that the engine rpm sounds like it momentarily drops down when this problem occurs, although the rpm readout does not change. However, I can easily increase the engine RPM by pushing the lever, it just does not transfer to the prop, which seems to me like gearbox trouble.

All comments/suggestions appreciated.  We don't really want to give up on our summer cruising, and apart from that its cold back in Sydney!

Thanks all.

Dean

SY Stella 

Amel 54#154