Transmission slipping
 

Does anyone have experience with an anti-slip additive for marine
transmissions? We have a Hurth HBW-150 R2 transmission that is
slipping, and we may have to alter our cruising plans as a result.. I
really don't want to continue without a workable transmission as I've
seen too many situations where sail alone was inadvisable, especially
in some of the Bahama cuts..

We changed the fluid, checked the linkage, and have been babying it
since first noticed.. It doesn't have an oil cooler, and I'm aware
that might help, but what we have is what we have..

Anyone with suggestions?

Diana

Transmission slipping
 

"Dr. Di" wrote in message
...
Does anyone have experience with an anti-slip additive for marine
transmissions? We have a Hurth HBW-150 R2 transmission that is
slipping, and we may have to alter our cruising plans as a result.. I
really don't want to continue without a workable transmission as I've
seen too many situations where sail alone was inadvisable, especially
in some of the Bahama cuts..

We changed the fluid, checked the linkage, and have been babying it
since first noticed.. It doesn't have an oil cooler, and I'm aware
that might help, but what we have is what we have..

Anyone with suggestions?

Diana


Yes, I understand that a handful of beach sand does wonders.

--
Gregory Hall

Transmission slipping
 

"Dr. Di" wrote in message
...
Does anyone have experience with an anti-slip additive for marine
transmissions? We have a Hurth HBW-150 R2 transmission that is
slipping, and we may have to alter our cruising plans as a result.. I
really don't want to continue without a workable transmission as I've
seen too many situations where sail alone was inadvisable, especially
in some of the Bahama cuts..

We changed the fluid, checked the linkage, and have been babying it
since first noticed.. It doesn't have an oil cooler, and I'm aware
that might help, but what we have is what we have..

Anyone with suggestions?

Diana

I had a somewhat smaller Hurth (28 hp) that slipped and this caused a delay
in engagement although it did finally pick up the drive but it was a worry
especially in docking situations and I could never be quite sure when
revving up the engine whether the extra revs were in fact being transmitted
to the prop or whether the extra torque was causing more slippage..
Spoke to a Hurth engineer who said that the clutch plates has probably come
to the end of their life and needed changing. Maybe the previous owner of
the boat had not slowed the engine before going from ahead to astern.
Anyway, the bad news was that the cost of the new plates plus labour meant
that it was more economical to replace the whole box at a cost of about
£900.
Considring this, plus the hassle of getting the engine out from under the
cockpit to remove the box I decided to put back a new engine and gearbox
while Ii was at it as this would add value to my yacht as well as ensuring
reliability.
These boxes are small and precision made and should engage with a hard
'click' and no slippage so I cannot offer much hope for an easy solution..

Transmission slipping
 

Dr. Di wrote:
Does anyone have experience with an anti-slip additive for marine
transmissions? We have a Hurth HBW-150 R2 transmission that is
slipping, and we may have to alter our cruising plans as a result.. I
really don't want to continue without a workable transmission as I've
seen too many situations where sail alone was inadvisable, especially
in some of the Bahama cuts..

We changed the fluid, checked the linkage, and have been babying it
since first noticed.. It doesn't have an oil cooler, and I'm aware
that might help, but what we have is what we have..

Anyone with suggestions?

You cannot buy a mechanic in a can....

Cheers
Marty

Transmission slipping
 

On 2008-03-17 15:20:30 -0400, Dr. Di said:

Does anyone have experience with an anti-slip additive for marine
transmissions?

We changed the fluid, checked the linkage, and have been babying it
since first noticed.. It doesn't have an oil cooler, and I'm aware
that might help, but what we have is what we have..

Anyone with suggestions?

Diana

I do believe you should pull the tranny, break it down, and replace the
worn parts. When a wet clutch stops working, there are often other worn
parts. I'd pay particular attention to the spring(s), which do get weak
over time. (Note: this is from motorcycle maintenance; I've not had to
touch a boat transmission except to change the oil.)

--
Jere Lull
Tanzer 28 #4 out of Tolchester, MD
Xan's pages: http://web.mac.com/jerelull/iWeb/Xan/
Our BVI trips & tips: http://homepage.mac.com/jerelull/BVI/

Transmission slipping
 

On Mon, 17 Mar 2008 15:20:30 -0400, Dr. Di
wrote:

Does anyone have experience with an anti-slip additive for marine
transmissions? We have a Hurth HBW-150 R2 transmission that is
slipping, and we may have to alter our cruising plans as a result.. I
really don't want to continue without a workable transmission as I've
seen too many situations where sail alone was inadvisable, especially
in some of the Bahama cuts..

We changed the fluid, checked the linkage, and have been babying it
since first noticed.. It doesn't have an oil cooler, and I'm aware
that might help, but what we have is what we have..

Anyone with suggestions?

Diana

I guess the first question is how do you know that it is slipping?

But if you are positive that the transmission is slipping then the
only solution is to rebuild it. A Hurth is a very simple transmission
- two clutch packs and a second shaft and gear set to reverse the
output rotation. If it is slipping then the clutch plates are worn and
nothing you can do is going to make any real difference.

An oil cooler won't make any difference at this stage but if you do
rebuild then adding a cooler might make the rebuilt box last longer
next time.

Foley Marine is a good source of parts and information regarding Hurth
boxes although there are plenty more on the net.

http://www.foleyengines.com/Home.aspx


Bruce-in-Bangkok
(correct email address for reply)

Transmission slipping
 

I didn't measure the differences in shaft speed, mainly because I have
no way to do it.. But the transmission overheats, and the boat speed
through the water decreases without any change in engine RPM's..

Thanks for your input Bruce, as well as everyone else who attempted to
help.. I guess it's time to consider pulling and rebuilding the
transmission..

Are you really in Bangkok? I think Thailand is a great place to visit,
with very friendly people... At least I found it so...

Diana

On Tue, 18 Mar 2008 09:36:53 +0700, Bruce in Bangkok
wrote:

On Mon, 17 Mar 2008 15:20:30 -0400, Dr. Di
wrote:

Does anyone have experience with an anti-slip additive for marine
transmissions? We have a Hurth HBW-150 R2 transmission that is
slipping, and we may have to alter our cruising plans as a result.. I
really don't want to continue without a workable transmission as I've
seen too many situations where sail alone was inadvisable, especially
in some of the Bahama cuts..

We changed the fluid, checked the linkage, and have been babying it
since first noticed.. It doesn't have an oil cooler, and I'm aware
that might help, but what we have is what we have..

Anyone with suggestions?

Diana

I guess the first question is how do you know that it is slipping?

But if you are positive that the transmission is slipping then the
only solution is to rebuild it. A Hurth is a very simple transmission
- two clutch packs and a second shaft and gear set to reverse the
output rotation. If it is slipping then the clutch plates are worn and
nothing you can do is going to make any real difference.

An oil cooler won't make any difference at this stage but if you do
rebuild then adding a cooler might make the rebuilt box last longer
next time.

Foley Marine is a good source of parts and information regarding Hurth
boxes although there are plenty more on the net.

http://www.foleyengines.com/Home.aspx


Bruce-in-Bangkok
(correct email address for reply)

Transmission slipping
 

On Wed, 19 Mar 2008 12:07:00 -0400, Dr. Di
wrote:

I didn't measure the differences in shaft speed, mainly because I have
no way to do it.. But the transmission overheats, and the boat speed
through the water decreases without any change in engine RPM's..
/snip/

These days, non-contact or optical tachometers are cheap - and popular
items at hobby shops. Look at this one, for example. $28.
Stick a piece of tape on the shafdt and have the tach look at it.


http://h1070530.hobbyshopnow.com/products/description.asp?prod=HAN156

Brian Whatcott Altus OK

Transmission slipping
 

On Mar 19, 2:59 pm, "Roger Long" wrote:
"Brian Whatcott" wrote
These days, non-contact or optical tachometers are cheap
http://h1070530.hobbyshopnow.com/products/description.asp?prod=HAN156

Thanks for the good link to what I was suggesting to someone else for
verifying their tach. ...

That would be me, I think. Very cool at that price. I'm not sure how
I'd get it to work on my saildrive though.

-- Tom.

Transmission slipping
 

On Wed, 19 Mar 2008 12:07:00 -0400, Dr. Di
wrote:

I didn't measure the differences in shaft speed, mainly because I have
no way to do it.. But the transmission overheats, and the boat speed
through the water decreases without any change in engine RPM's..

Thanks for your input Bruce, as well as everyone else who attempted to
help.. I guess it's time to consider pulling and rebuilding the
transmission..

Are you really in Bangkok? I think Thailand is a great place to visit,
with very friendly people... At least I found it so...

Diana



All the Hurths I've seen got pretty hot. hot enough that, while it
didn't burn your hand, you didn;t want to keep your hand on it very
long.

I am assuming that you have checked the oil.

Yes I am in Thailand, I live here permanently. We spend about half
our time in Bangkok and half in Phuket where we keep a 40' sloop.

Bruce-in-Bangkok
(correct email address for reply)

Transmission slipping
 

"Brian Whatcott" wrote in message
...
On Wed, 19 Mar 2008 12:07:00 -0400, Dr. Di
wrote:

I didn't measure the differences in shaft speed, mainly because I have
no way to do it.. But the transmission overheats, and the boat speed
through the water decreases without any change in engine RPM's..
/snip/

These days, non-contact or optical tachometers are cheap - and popular
items at hobby shops. Look at this one, for example. $28.
Stick a piece of tape on the shafdt and have the tach look at it.


http://h1070530.hobbyshopnow.com/products/description.asp?prod=HAN156

Brian Whatcott Altus OK

Sounds interesting, but why does it care how many blades are on the
propeller if it is only looking at the shaft?

Transmission slipping
 

On Thu, 20 Mar 2008 16:52:29 +0100, "Edgar"
wrote:

Sounds interesting, but why does it care how many blades are on the
propeller if it is only looking at the shaft?

It is designed to check RPMs on model airplanes where there is not
much shaft to work with.

Transmission slipping
 

On Thu, 20 Mar 2008 16:52:29 +0100, "Edgar"
wrote:


"Brian Whatcott" wrote in message
.. .
On Wed, 19 Mar 2008 12:07:00 -0400, Dr. Di
wrote:

I didn't measure the differences in shaft speed, mainly because I have
no way to do it.. But the transmission overheats, and the boat speed
through the water decreases without any change in engine RPM's..
/snip/

These days, non-contact or optical tachometers are cheap - and popular
items at hobby shops. Look at this one, for example. $28.
Stick a piece of tape on the shafdt and have the tach look at it.


http://h1070530.hobbyshopnow.com/products/description.asp?prod=HAN156

Brian Whatcott Altus OK

Sounds interesting, but why does it care how many blades are on the
propeller if it is only looking at the shaft?

Optical tachs sold to hobbyists often have that sophistication - that
you don't need, but can work with easily, I imagine?

Brian W