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Question about propellor movement when in drive

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dwaggle

New member
I have a Mercruiser Alpha One outdrive and have a question. When I have the boat in gear (Fwd)....I can NOT move the propeller counterclockwise. However, I can move the propeller in a clockwise movement...but there is a clicking or ratchet like sound.

Question: Is this normal???

When I ran the motor in drive, it was quiet and I did not notice the clicking sound. But whenever I turn the motor off and put it in gear, I can NOT move in counterclockwise, but move in clockwise motion with the clicking sound.

Thanks.
Douglas
 
Doug, this is the nature of Dog Clutch type gear engagement. You'll find the same to be true if you were to have the drive in REV.
It has to do with the ramping and cut of the FWD/REV Gears and Sliding Sleeve engagement teeth. (not the actual gear-to-gear Hypoid teeth)
These are ramped as to cause a pressure force as to maintain engagement.
They will "ratchet", so to speak (the clicking sound), when rotated in the direction of intended prop rotation.

Very hard to see in this image, but seq#53 is the sliding sleeve, and seq#'s 44 and 55 are the FWD and REV gears.
The three gears rotate consistantly with engine rpm!
The prop shaft becomes engaged only during sliding sleeve selection of either FWD or REV gear.

Alpha-one-lower-gear-case-layout-drawing.jpg


Here is a random sliding sleeve and two gears.
Note the incline and ramping of the Dog Teeth.
The makes for one way engagement only.

images

images
 
Last edited:
Thanks guys, this makes be feel a whole lot better. Really appreciate all the insight (and fact nothing else is wrong)(

Douglas
 
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