Le 11 janv. 2021 à 11:59, karkauai via groups.io <karkauai@...> a écrit :



Bill K,

Thank you for this clear explanation of the Hurth/ZF transmissions. I haven't read this anywhere before and have never understood why my helm has a sign that says in French, not to put in reverse while sailing. When I switched from AutoProp to be MaxProp, I read that I should put in reverse until it stopped turning, then back to neutral. I have just finished a maintenance of the Autoprop and reinstalled it to see how it performs compared to the MaxProp.  I now know that if it turns while sailing, it is safe to put the transmission in forward, but not reverse.

Now for the next question...

When I repowered from Volvo TMD22 (78HP} to Yanmar 4JH4HTE, (110HP), I was assured by the Yanmar dealer and mechanic (Danny Ramos in Fajardo; top Volvo mechanic in the Caribbean at the time) that the existing transmission was ok to reuse.  It has had no problems after ~1200 hours using the MaxProp.  But now I am worried that it may not be quite up to the job.  Does anyone have thoughts or recommendations about that? 

Should I just replace it with a new, more

robust one? If I use the Z25F, that means adding a shaft brake, right? Are there other robust mechanical transmissions that wouldn't require the brake? Any downsides to that?

Or have the transmission inspected, and put it back in if everything looks OK?

Or, with 1200hours already on the transmission with the new engine, just assume it is Ok and leave it alone?

Thanks again Bill K, your post is a game-changer for me!

Happy New Year, everyone!

Kent & Iris

Kristy

SM 243

--
Kent & Iris

KRISTY

SM243

All,

I have a Eumenia Mini 5500 Dishwasher, and would like keep Aquarius stock.  But, need to get spare parts for the dishwasher.  I have emailed ersatzteile@schabauer-service dot at , but have not received a response.  The evacuation pump is out, and might try to find a replacement which is similar if I can not get the exact replacement.

Any thoughts on what I should do.

Thanks!

Kenneth Powers
Aquarius sm2k262

Le 10 janv. 2021 à 19:17, CW Bill Rouse <brouse@...> a écrit :



Juan,

You should have something like this. It will help you with many things:

<image.png>

If you have a meat thermometer, it can work. Something like this:

<image.png>

	CW Bill Rouse Amel Owners Yacht School +1 832-380-4970 | brouse@... Address: 720 Winnie, Galveston Island, Texas 77550  Website: www.AmelOwnersYachtSchool.com

View My Training Calendar

On Sun, Jan 10, 2021 at 4:39 PM Juan de Zulueta <jdezulue@...> wrote:

Bill, I changed the impeller but I did not check temperature of the oil neither of the exhaust
i am not sure what type of thermometer I can use .
I checked coolant level , see water temp, coolant temp in the hoses before and after heat exchanger but only by hand and not using thermometer
 


thanks again for your answer

On 11 January 2021 at 14:18 "Karen Smith via groups.io" <karenharmonie@...> wrote:

Mark,

I think you are mixing up the ZF25M transmission and the ZF25. The document you reference is for a ZF25M, not the ZF25.  This has been a common source of confusion on the forum, since both of these are the common transmissions used in many Amel boats. The similar model numbers for two very different machines has always been an issue.

This is my understanding of this un-necessarily complicated issue:

The ZF25M is a smaller, lower horsepower rated, transmission that shifts mechanically. I believe none of these transmissions were ever fitted with a shaft brake, because none was needed.  The ZF25, even though it has a very similar part number, is a very different beast.  I doubt the ZF25M and the ZF25 have any parts in common.  The ZF25 is a higher horsepower rated, hydraulically shifted, transmission.  As far as I know (and this might not be correct) the Volvo TMD22 engines all had ZF25M and the Yanmars all had ZF25.  Note that these model numbers changed when the original Hurth brand was bought out by ZF.

As the document you quoted points out, the ZF25M can free-wheel without damage, other than routine wear on bearings and seals. With a normal fixed prop or a MaxProp, putting it in reverse will lock the rotation.  The AutoProp is a different story.  It rotates in the opposite direction when free-wheeling, and needs to be put in FORWARD to lock it.  The rule for operation should be “Do not allow the transmission to free wheel while in gear—ever.”  If the prop rotates while in reverse, put it in forward.  And the other way round.

The ZF25 relies on the hydraulic pressure generated by the rotating input shaft (from the engine) to shift.  If the engine is not turning, it will always be in neutral, and neither forward nor reverse can be engaged no matter what the position of the shift lever.  Therefore, the prop will always spin when the engine is not running.  Most hydraulic transmissions require the engine input shaft to be turning to pump the fluid internally to lubricate the moving parts. The ZF25, however, is allowed to rotate with the engine off.  It will be noisy, and add routine wear to the bearings and seals. There is no way to stop the rotation without a shaft brake.

Here are the rules:

If you have a Volvo with a ZF25M transmission:

• Sailing in neutral is acceptable with any propeller. The prop WILL spin with a fixed prop or an AutoProp, and MIGHT spin with a MaxProp. While spinning, the prop is noisy and adds routine wear and tear to the bearings and seals. 
• With a MaxProp or a fixed prop, you can sail in reverse and the prop will not turn. This is acceptable.  
• With a fixed prop, if you sail in forward, the propeller will spin, and the transmission will be damaged quite quickly.
• With a MaxProp, if you sail in forward, the propeller MIGHT spin, and if it does the transmission will be damaged quite quickly. 
• With an AutoProp, you can sail in forward and the prop will not turn. This is acceptable.
• With an AutoProp, if you sail in reverse, the propeller will spin, and the transmission will be damaged quite quickly.

If you have a Yanmar with a ZF25 transmission,

• With any propeller, the shaft can spin when sailing. This is acceptable, again, other than the noise and additional routine wear on bearings and seals.
• The only way to stop this rotation is to use a shaft brake.

Bill Kinney
SM160,  Harmonie
The boat is in Charleston, we are in Antigua finishing up a delivery.

On 11/01/2021, at 9:40 AM, Rod Glassford <rod@...> wrote:

Hello all Amel owners! I’m new to the site, and too our Amel . We own a 1986 Amel Maramu and need too get a replacement (spare) headsail furling motor. Does anyone know what is available?
cheers,
Rod