Another shifting issue

[shiloh87]

Hello all, just jointed up, great forum, lots of information here.
I`m having issues getting my stern drive to shift, a little back story first.
Started a boat project 2yrs ago and decided to build a deepV16(donzi sweet 16ish) cold molded plywood/mahogany and cedar, epoxy glassed, the boat is now finished.
Bought a donor boat for the running gear, 1984 470, and stern drive Alpha1 I believe, eng#6684502, drive#6683465. The engine was seized at 165hrs, but being a bit of a motor-head, I did a ground up rebuild this past winter, all done and purrs like a kitten. The stern drive needed a good cleaning paint and decals, impeller, also rebuilt the power trim system, all good.
The problem I`m having is, all I can get from the shifter is forward 12:00, neutral at 11:00 and no reverse (moving the shift shaft by hand) Stern drive is installed, cables disconnected at the engine.
Was in forward when I installed the LU, prop locked in forward (prop rotates CW when in forward) could the lower shift shaft be off by a spline or is the lower pooched (fingers crossed)
The thing is when the LU was on the bench I could shift it, forward neutral and reverse??
I know this has been asked a gazillion times, but I`m befuddled at this point.
Cheers

 

[Bt Doctur]

Remove the complete drive and verify shift operation. A bad shift cable will prevent full travel of the slide if muck and mud got behind and into the slide. Disconnect the lower shift cable and from outside the boat move the slide inward ,it should bottom out inside the case.
If you installed it with the shoe in a srtaight line and the prop locked CCW (forward) you assembled it correctly

 

[shiloh87]

Cables are good, all disassembled cleaned and lubed.
Q. this confuses me, the prop rotates CW(RH) when in forward, why rotate CCW to lock it in forward, when I do this CCW the prop rolls over making a clacking sound but is locked to the CW direction, as in reverse before installing the LU, which I might add I`ve had off 4 times in the last week, thank god I`m retired...lol
I guess I need clarification, if when rotating CCW it should lock like it does if rotating CW, that makes no sense, CCW the prop will stop but if you continues it clacks over, but remains engaged if rotated CW.
Hows that for confusing.

 

[shiloh87]

I also kind of figured this LU would be coming off again.......
I discovered this issue after making all the adjustments to the cables as per my Merc Manual, it would go into neutral, forward but no reverse.

 

[Bt Doctur]

The prop is locked against the dogs and turning clockwise for fwd using engine power.. So if you manually shift into fwd by turning the shift shaft fully clockwise the prop will be locked trying if you try to turn it CCW/ If you were to hold the shift shaft by hand and rotate the prop cw now ,the shift shaft would ratchet.
With reverse , shifting into reverse the prop will now lock CW and if you hold pressure on the shift shaft it will ratchet turning CCW

Like I said. Remove the cable inside the boat and from outside see if the slide will bottom out in the housing.

 

[Bt Doctur]

 

[Bt Doctur]

the green is crud preventing full travel for reverse

 

[achris]

The reason the prop locks CCW and ratchets CW (in forward) is because of the ramps on the dog clutch. The engine is trying to spin the prop CW (as viewed from behind) and the water is resisting that (you can think of it as the water trying to turn the prop 'the other way', CCW), and that's why the prop locks CCW, so the engine can turn it. Now visualise the boat moving through the water at say, 10 knots. Suddenly you pull the throttle back (like pulling your foot off the pedal when driving down a road), the boat doesn't instantly stop, we hope. Just like the diff in the car, the gears go into the 'overdrive' side. Only on the case of a MerCruiser lower gear set they go into the ramps of the clutch and hence the ratcheting.... The movement of the boat through the water is faster than the engine is trying to turn the prop, the prop now tries to turn the engine but, ratcheting....

HTH,

Chris...

 

[Paintman1960]

The reason the prop locks CCW and ratchets CW (in forward) is because of the ramps on the dog clutch. The engine is trying to spin the prop CW (as viewed from behind) and the water is resisting that (you can think of it as the water trying to turn the prop 'the other way', CCW), and that's why the prop locks CCW, so the engine can turn it. Now visualise the boat moving through the water at say, 10 knots. Suddenly you pull the throttle back (like pulling your foot off the pedal when driving down a road), the boat doesn't instantly stop, we hope. Just like the diff in the car, the gears go into the 'overdrive' side. Only on the case of a MerCruiser lower gear set they go into the ramps of the clutch and hence the ratcheting.... The movement of the boat through the water is faster than the engine is trying to turn the prop, the prop now tries to turn the engine but, ratcheting....

HTH,

Chris...

Fantastic explanation,
I had to read it a couple times to understand it !!
Thank you Sir!!

 

[shiloh87]

Chris, excellent explanation, I get it now.
I now realize I`ve installed the LU while in reverse, That makes sense now.
So back to the shop to lower the LU and sort out my mistake.
Ounce I get this fixed I`ll report back,
Thank-you gentlemen greatly appreciated.
Rick

 

[shiloh87]

Like I said. Remove the cable inside the boat and from outside see if the slide will bottom out in the housing.

No muck or gunk, during the restoration, everything was thoroughly cleaned and lubed, I`m anal that way, I`ve spent most of my life restoring vintage motorcycles.
This boat project is a homage to my father, he was a master mariner and didn`t get the whole motorcycle thing.
He always said I should be building boats, a little too late perhaps, but I`m sure he`d be pleased.
There were always boats at the dock while growing up, but I was never really into it then, so this has been a real learning experience for me, my only regret is that Pops isn`t around to see it or help.
Cheers

 

[shiloh87]

Got at it this morning, dropped the LU down enough to get at stuff, followed the instructions to the letter, readjusted the cabling, every thing in spec and viola, I now have a properly functioning stern drive.
I had the gears locked in reverse that`s why it didn`t work.
Now to get this thing in the water and fine tune the engine and get her broke-in, 20hrs according to the manual, couple weekends out on Georgian bay should do it, just need some warmer weather, I don`t do cold very well.
Thanx again for the help

 

[achris]

.... I don`t do cold very well....

You and me both!