stern drive shift adjustment?

W

wino

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Joined
Oct 2, 2005
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19181
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I have an older Alpha..some call it an MR some call it Alpha One..I don't know.What happened is I replaced the carburetor and since then I have had shift trouble.It will shift into forw. but not back into neutral and reverse when engine is running.I was told that the piece in the stern drive lower end(shift fork etc.) was probably worn so I rebuilt the lower end replacing that and the shift spool and some bearings etc.I couldn't get it to adjust even then.So I took it to the marina and they adjusted it and it worked once($80 gone).So I replaced all the cables and bushings and anything to do with the shifting except the shifter itself which I am sure is fine.The book I have seems to be screwed up in their instructions so I figured to come here.I have pics of the adjusting linkage if I can post them somehow.
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If anyone has experience and can talk me through this I would be eternally grateful!

Thanx
 
I'm guessing you have a straight 6 because of the cable configuration.(all this info should be included in your post).

Sticking lower shift cable is the major cause of your problem.

I guess you replaced the lower shift cable. Put remote shift into neutral. Remove the lower cable at the shift plate and shift forward/Rev as someone turns prop in both directions. You're trying to define the cable end position in neutral(the prop will turn freely in both directions).

Hopefully the lower shift cable will connect back up. If not, remove adjusting barrel and turn untill the cable end will go back on. Now you should be very close. Now shift into forward and turn the prop clockwise and you should hear and feel a clunking as the dog clutch rides up and falls off the ramped gears. Now put in reverse and turn prop counter clockwise and feel the clunking. You want the clunking to be the same in both forward and reverse. That will mean the shifter is adjusted right in the middle. To adjust the shifter, remove the remote cable adjusting barrel at the shift plate and turn inward or outward a turn or two and recheck prop clunk. Adjust to get equal clunk.

Now, the shift interrupt switch may be bad but it's the little square box with a little white roller that sits in the middle of the little 'U' in the 'V' plate. Unless the switch is bad everything here should be working OK 'cuz you replaced the lower shift cable.

OH, And your pics aren't very clear. Plus, back off a bit to get a wider pic of things.
 
quote:
Originally posted by jtybt15

"OH, And your pics aren't very clear. Plus, back off a bit to get a wider pic of things."

Click to expand...


And take a safe boating class. For added safety...wear a PFD. Or, at least, take a picture of a PFD and bring it along with you. ;)
 
jtybt
I agree that the carburetor linkage and interupt switch pics aren't the greatest but they are secondary.If you could describe to me like you would to a child maybe I would understand better.Why wouldn't the lower shift cable hook back up?Remove lower shift cable at shift plate...and shift for/rev with what,the end of the lower cable?What adjustment is the long slot for?When I remove lower cable at shift plate you mean take out the cotter pin and pull out the brass barrel from the groove it sits in?It seems simple to lots of people but none have bothered to help me fix it.

Thanx
 
OK, Sorry. Disconnect lower cable end and move in/out( shift forward/reverse) as prop is turned. There will be a place where the prop will turn freely. That is neutral. With the remote in neutral the lower shift cable end should slide back on the post. If not, slide barrel out and re-connect lower cable end and turn barrel until it will slide back in position. That will place you very close to correct adjustment. Final adjustment is done with barrel on remote cable.

That slot adjustment adjustments total amount of throw of lower cable. Shouldn't have to mess with it. Looks like you've been doing just that. Set it about in the middle. Messing with the slot position may even cause a problem with the reverse cut-out.
 
jtybt15
No need to apologize.I have been trying this for an extremely long time on and off.I would just get so frustrated because anyone I asked around here says it is so simple but none can figure it out even after replacing all there is to replace.I have spinal disease and had a badly broken neck three years ago so working on this is not as enjoyable as it should be.
Anyway those instructions seem much clearer.After that I use the ones (instructions) to adjust for clunk, correct? Also,you must understand how much I appreciate you taking the time out of your life to help me understand this.I love the water,I live on the coast in Nova Scotia ,and my boat,although it isn't much,is mine and my grandmothers both love going out to watch the whales and porpoises.

Thank You
 
That's what we try to do here....help.

If you can understand how everytning works, it's easier to figure out how to fix it.

On the shifting, there is what is called a dog clutch. It's simply a gear with teeth on the side instead of the edge. It slides between two other gears. It has a total side to side movement of about an inch. All you're trying to do is set that gear in the exact middle of it's travel while in neutral. The equal clunking tells you that it's engaging both the forward and reverse gear the same distance...so, in the middle.
It IS really simple after you understand the principle.

Good luck. I hope you have fun out there.
 
Well I did manage to rebuild that part of it so I do understand what is in there,just after trying to read this old manual with about six different ways to adjust the different cables my head is spinning.I have also had it to work in the yard but when I put in water it seemed a bit wrong again.It doesn't seem like too much play in prop though.When I can get someone to spin the prop for me I will give it another go.

Thanx Again
 
Just shift into gear and go down and turn prop yourself. The prop turner is the one who can tell the amount of clunk, anyway.
 
well I adjusted the cable to get about an equal amount of clunking out of both forward and reverse.Neutral was fine.Launched boat and still have to tug at it to get shifted back into neutral from forward or reverse.Where should I adjust now to fine tune?
 
I also noticed a small amount of water coming in by steering arm,any ideas about this?
 
Hard to get back into neutral(when running) is because the shift interrupt switch isn't working. I'm taking for granted that the lower cable moves forward/reverse smoothly.

The dog clutch has a very slight undercut to help insure that it doesn't pop out of gear. It also requires pressure to be slackened when trying to bring back to neutral. The shift interrupt switch momentarily cuts juice to the coil which so the engine stalls for a micro second...just enuff to slacken pressure on the dog clutch.

The shift interrupt switch is the little switch with the little white roller on the shift plate. The roller rides in the 'U' groove of the pivoting 'V' plate. The 'V' plate should move the roller out of the bottom of the 'U' which when shifting into neutral and the switch cuts juice. The V plate should immediately return to the center position.

Now, either the lower cable is binding in the housing(from corrosion) or the interrupt switch is broken or the wires aren't connected.

First make sure switch and V plate moves like it's supposed to.

Then, with engine running, push the roller or swing the V plate to activate the switch...which should kill the engine.

Let us know what happens.

The water could be leaking from the upper swivel shaft.
 
That is what I thought.I moved the switch lever by hand and it does kill the engine,but it is an old switch and I am sure you know that a newer switch will actually click when you actuate it and this one doesn't.First I will try to bend the lever just slightly to have it engage the switch more firmly if that doesn't work I will try and find a replacement.

The upper swivel shaft was a used replacement and maybe the seals won't seal it properly.Almost impossible to find the correct seals for it.Any suggestions for me?

Thanx for all help
 
and them swivel shafts are expensive. Mine was corroded so I dipped it in muriatic acid and filled the low spots with epoxy mixed with fumed silica and aluminum powder.

They also have a SS replacement.

The newer switch works differently and I haven't had a chance to see if it will work as a subsitute for the older style. I have repaired a couple of the older switches, though.

Your problem sounds like the switch isn't engaging so bending the lever/arm should work.
 
Took the switch off and cleaned it as best I could put it back on but haven't tried it yet.Looked on internet for micro switches and saw lots so I have to take it back off and make all the measurements to see if I can find a match.
Where did you get the fumed silica and aluminum powder or is it in the epoxy?
 
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