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Master Mariner
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Discussion Starter #1
Does anyone have or have heard of a "Proplock" by a company in Maine called Sarns Machine? It is a hydraulic shaft brake last manufactured in the early '90s.
I have all the parts but apparently, if hooked up incorrectly, it will trash the Velvet Drive transmission, so I need the installation instructions.
Thanks
 

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Learning the HARD way...
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I have heard of them, but never seen one. The thought of the possibility of putting the transmission in gear with this engaged scares me.
 

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Hey capta ! They were in Southwest Harbor, Me. and Gainesville, Fla. It should look like a disc brake, supposedly hooked up between the coupler ! from the pics ! I did a search Sarns Machine prop shaft lock. Came up with pics and a couple of articles ! Good luck !!!
 

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Master Mariner
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Discussion Starter #4
Hey capta ! They were in Southwest Harbor, Me. and Gainesville, Fla. It should look like a disc brake, supposedly hooked up between the coupler ! from the pics ! I did a search Sarns Machine prop shaft lock. Came up with pics and a couple of articles ! Good luck !!!
Thanks. I've already contacted half a dozen Sarns Machine companies across the country and none had anything to do with Proplock. All I need is the installation instructions as I have all the parts. I can figure out everything thing except the hydraulic connection, but as stated above, apparently, if hooked up incorrectly, it will trash the Velvet Drive transmission.
 

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Is the connection to a single hydraulic hose on a diaphragm spring loaded calliper? Maybe it is connected to the cooler output for its operating pressure, T'eed in there ( upper rear st'brd side ) would see the pressure to the cooler.. Been 30 yrs since I played with one so just thinking sporadically.
 

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OK, I have to ask - what function does a shaft lock serve? Is this just to stop the prop turning when sailing?
 

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On a velvet drive the oil is cooled by a geroter gear pump on the input shaft.this oil operates the bands and disks. When engine is running cooling happens. When sailing ,the prop turns the back half of the gear box and creates heat that stays there because the gerotor pump is not functioning unless engine is running. This is not good as heat and unnecessary wear should be avoided by locking the shaft. Some gear boxes aren't so fussy in this department.
 

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Master Mariner
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Discussion Starter #9
OK, I have to ask - what function does a shaft lock serve? Is this just to stop the prop turning when sailing?
Yep, you hit the nail right on the head.
This one releases when the engine starts and stops the shaft turning, like a big disc brake, The disc is at the coupling and the hydraulic ram is attached to the boat in the bilge. Great system, if one doesn't have 4 to 6 grand for a MaxProp.
 

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Master Mariner
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Discussion Starter #10
On a velvet drive the oil is cooled by a geroter gear pump on the input shaft.this oil operates the bands and disks. When engine is running cooling happens. When sailing ,the prop turns the back half of the gear box and creates heat that stays there because the gerotor pump is not functioning unless engine is running. This is not good as heat and unnecessary wear should be avoided by locking the shaft. Some gear boxes aren't so fussy in this department.
Borg Warner now states that at moderate sailing speeds it is OK to let the shaft spin. Roughly 10 knots or less.
My Velvet Drive has a real heat exchanger to cool the oil, but it obviously doesn't cool if the engine is not running.
 
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