Help! Has my Yanmar transmission been destroyed?
 

Here is the whole embarrassing story. A friend was at the helm, we
were motoring down the channel at 2600 RPM. I have a 3 cylinder Yanmar
engine. I was dealing with the sheets. I asked my friend to slow down.
He got confused between the transmission and the throttle. Instead of
cutting back the throttle, he threw the transmission from forward to
reverse! There was a terrible noise as you can imagine. My friend
immediately realized that he had made a mistake and shifted to
neutral. After that, the engine and transmission seemed to behave
normally but now I am not as confident as I was. So what do you think?
Will I need a new transmission? And what about the folding prop? Any
advice would be greatly appreciated.
Thanks,
Ken

Help! Has my Yanmar transmission been destroyed?
 

Ken wrote:
Here is the whole embarrassing story. A friend was at the helm, we
were motoring down the channel at 2600 RPM. I have a 3 cylinder Yanmar
engine. I was dealing with the sheets. I asked my friend to slow down.
He got confused between the transmission and the throttle. Instead of
cutting back the throttle, he threw the transmission from forward to
reverse! There was a terrible noise as you can imagine. My friend
immediately realized that he had made a mistake and shifted to
neutral. After that, the engine and transmission seemed to behave
normally but now I am not as confident as I was. So what do you think?
Will I need a new transmission? And what about the folding prop? Any
advice would be greatly appreciated.
Thanks,
Ken
Well, I've done that more than once without trashing a tranny. Of
course, I suppose it depends on just how fast the shift actually was -
usually my "panics" are anticipated so it isn't quite as bad as it
might be.

As for the prop, I don't see how that would be hurt. If it was a
feathering prop, it would reverse rather quickly, but a folder doesn't
do anything.

Help! Has my Yanmar transmission been destroyed?
 

Ken,

Your tranny is probably OK. If it was me, I'd have a check of the thrust
bearing, Folding Prop Blades and Pins and watch the packing gland for
excessive leaky. You're probably OK. Those Little Univ are tough little
engines. It's the crap thats hooked to them that will give you the
problems

Happy Motoring; I HOPE!!


http://community.webtv.net/tassail/ThomPage

http://community.webtv.net/tassail/Pneuma

Help! Has my Yanmar transmission been destroyed?
 

Ken wrote:
Here is the whole embarrassing story. A friend was at the helm, we
were motoring down the channel at 2600 RPM. I have a 3 cylinder Yanmar
engine. I was dealing with the sheets. I asked my friend to slow down.
He got confused between the transmission and the throttle. Instead of
cutting back the throttle, he threw the transmission from forward to
reverse! There was a terrible noise as you can imagine. My friend
immediately realized that he had made a mistake and shifted to
neutral. After that, the engine and transmission seemed to behave
normally but now I am not as confident as I was. So what do you think?
Will I need a new transmission? And what about the folding prop? Any
advice would be greatly appreciated.
Thanks,
Ken

Should be OK, drain the fluid and look for metal in the fluid.

Good argument for a proper throttle.

Joe

Help! Has my Yanmar transmission been destroyed?
 

Ken wrote:
Here is the whole embarrassing story. A friend was at the helm, we
were motoring down the channel at 2600 RPM. I have a 3 cylinder Yanmar
engine. I was dealing with the sheets. I asked my friend to slow down.
He got confused between the transmission and the throttle. Instead of
cutting back the throttle, he threw the transmission from forward to
reverse! There was a terrible noise as you can imagine. My friend
immediately realized that he had made a mistake and shifted to
neutral. After that, the engine and transmission seemed to behave
normally but now I am not as confident as I was. So what do you think?

I think if there were a problem, there are a couple easy
ways to find out.


Will I need a new transmission? And what about the folding prop? Any
advice would be greatly appreciated.


Joe wrote:
Should be OK, drain the fluid and look for metal in the fluid.


Don't have to drain it, just pull out the dipstick and stick
a magnet down there. Or send a sample to an analysis shop (a
good idea in any event).

Good argument for a proper throttle.


What's "proper"?

2 other things come to mind... operating temp (I bet you
don't know what the operating temp was before) and the
linkage. At least the linkage can be carefully inspected &
replaced if need be.

Fresh Breezes- Doug King

Help! Has my Yanmar transmission been destroyed?
 

DSK wrote:

Good argument for a proper throttle.


What's "proper"?

http://users.sisqtel.net/jkriz/drawings/MT2.jpg

A Morse like I have on RedCloud is a proper throttle, you have to
throttle back to idle to shift.

Face it, having a seperate shift and throttle control sucks.

Morse also makes some very nice air controls.

Joe





2 other things come to mind... operating temp (I bet you
don't know what the operating temp was before) and the
linkage. At least the linkage can be carefully inspected &
replaced if need be.

Fresh Breezes- Doug King

Help! Has my Yanmar transmission been destroyed?
 

I'm surprised the prop didn't come thru the bottom of the boat.

Help! Has my Yanmar transmission been destroyed?
 

"Ken" wrote in message
...
Here is the whole embarrassing story. A friend was at the helm, we
were motoring down the channel at 2600 RPM. I have a 3 cylinder Yanmar
engine. I was dealing with the sheets. I asked my friend to slow down.
He got confused between the transmission and the throttle. Instead of
cutting back the throttle, he threw the transmission from forward to
reverse! There was a terrible noise as you can imagine. My friend
immediately realized that he had made a mistake and shifted to
neutral. After that, the engine and transmission seemed to behave
normally but now I am not as confident as I was. So what do you think?
Will I need a new transmission? And what about the folding prop? Any
advice would be greatly appreciated.
Thanks,
Ken

He probably slightly rounded a few gear teeth, but not much else. Might be
worthwhile to change the fluid and check for metal fragments or "filings."

Better yet, I think you should send that transmission to me for disposal.

Max

Help! Has my Yanmar transmission been destroyed?
 

"Joe" wrote in message
oups.com...

Face it, having a seperate shift and throttle control sucks.

The vast majority of boats have exactly that, however. Proper usage isn't
hard to learn, and making sure crew know how to use it is also imperative.

Max

Help! Has my Yanmar transmission been destroyed?
 

Check for metal filings in the transmission oil and do a gear vibration
analysis:

http://www.vibcons.com/vibration_data_collector.shtml

http://www.reliabilitydirect.com/vib...ts/vib_pen.htm

Here's some people that can do it for you:

http://www.thomasnet.com/products/vi...1870204-1.html

You can actually do the gear vibration analysis on the audio input port of
your pc.



"Ken" wrote in message
...
Here is the whole embarrassing story. A friend was at the helm, we
were motoring down the channel at 2600 RPM. I have a 3 cylinder Yanmar
engine. I was dealing with the sheets. I asked my friend to slow down.
He got confused between the transmission and the throttle. Instead of
cutting back the throttle, he threw the transmission from forward to
reverse! There was a terrible noise as you can imagine. My friend
immediately realized that he had made a mistake and shifted to
neutral. After that, the engine and transmission seemed to behave
normally but now I am not as confident as I was. So what do you think?
Will I need a new transmission? And what about the folding prop? Any
advice would be greatly appreciated.
Thanks,
Ken