Alpha one shifting issue

skunked · May 13, 2008

I have a Mercruiser 5.7L/Alpha one combo that started acting up after I hired a "mechanic" to replace the impeller/gear oil as a side job. The boat ran great for about 20 minutes on the lake after the work was done and then started to shift from forward to neutral and back and forth while the throttle was in the forward or neutral position. After researching I have found that possibly some part of the shift linkage was not "lined up" when the lower portion of the drive was reinstalled. I actually helped this guy do the work and pull the drive and I know for a fact the boat was left in neutral while all the work was done. I'm just trying to find out if this would cause the symptom I'm describing and whether or not I can expect some other damage from this "mechanics" lack of knowledge.

Thanks in advance guys

krisnowicki · May 13, 2008

Re: Alpha one shifting issue

When you pull the drive you need to have the boat and OD in Fwd... Usually keeping a bungee on the prop will keep it in fwd. So when you put it back together it will stay in fwd.

buggiedad_67 · May 13, 2008

Re: Alpha one shifting issue

did you check the shift cable to make sure it shifted smoothly, most change out that cable when taken down , that way you know its good when it goes back together,

skunked · May 13, 2008

Re: Alpha one shifting issue

krisnowicki said:
When you pull the drive you need to have the boat and OD in Fwd... Usually keeping a bungee on the prop will keep it in fwd. So when you put it back together it will stay in fwd.

so based on this requirement and knowing that it was not done it's fair to make the assumption that this is what caused the problem. Correct?

skunked · May 13, 2008

Re: Alpha one shifting issue

buggiedad_67 said:
did you check the shift cable to make sure it shifted smoothly, most change out that cable when taken down , that way you know its good when it goes back together,

I don't remember him checking that. Good point.

Don S · May 13, 2008

Re: Alpha one shifting issue

Was the complete outdrive removed to replace the impeller? He may have removed only the lower unit. Many do.
If only the lower was removed, then it doesn't have to be in forward. Makes it a little easier, but isn't necessary. If the complete outdrive was removed, it had to be in forward or the shifts can/will be bent.
Did anyone check to see if fwd, neutral, and rev. worked after the work, or was this a put it together, float it off the trailer an go for broke?

Either way, was the gear lube refilled?

skunked · May 13, 2008

Re: Alpha one shifting issue

Don S said:
Was the complete outdrive removed to replace the impeller? He may have removed only the lower unit. Many do.
If only the lower was removed, then it doesn't have to be in forward. Makes it a little easier, but isn't necessary. If the complete outdrive was removed, it had to be in forward or the shifts can/will be bent.
Did anyone check to see if fwd, neutral, and rev. worked after the work, or was this a put it together, float it off the trailer an go for broke?

Either way, was the gear lube refilled?

Just the lower half was removed and yes new gear lube was pumped into the drive. I ran the boat in the driveway for about 20 minutes (idle in neutral) after the install with no issues. The next day we hit the water and the boat ran great for about 15-20 minutes and then started to act up.

ziggy · May 13, 2008

Re: Alpha one shifting issue

hows it work on land, not running. just running the shifter, do you have.
in fwd. prop locks ccw
in neutral, prop spins totaly free
in rev. prop locks cw
do you meet that criteria?

skunked · May 13, 2008

Re: Alpha one shifting issue

ziggy said:
hows it work on land, not running. just running the shifter, do you have.
in fwd. prop locks ccw
in neutral, prop spins totaly free
in rev. prop locks cw
do you meet that criteria?

I'll check.

skunked · May 16, 2008

Re: Alpha one shifting issue

ziggy said:
hows it work on land, not running. just running the shifter, do you have.
in fwd. prop locks ccw
do you meet that criteria?

yes it does lock in FWD ccw. When in reverse it makes a clicking noise spinning the prop ccw or cw.

ziggy · May 17, 2008

Re: Alpha one shifting issue

When in reverse it makes a clicking noise spinning the prop ccw or cw.

that aint right. drop the lower again and shift it on the bench. see if ya meet the criteria then to see if the lower is ok. assuming it does. ya can look up underneath the drive, lower removed, and shift it from the helm. watch the coupler move. the coupler should be straight fwd., in fwd. then swing towards port. as ya go to neu. then further to port for reverse.... if all is well, put helm in fwd. lock the prop ccw, and reinstall and see what happens....

this is a assembled 1 drive (very similar to yer alph1). the pic is the shift shafts coupled together in neutral. if it was in fwd. the coupler would be facing fwd. if it was in reverse, it'd be swung further to port than the pic.

liquidlew · May 17, 2008

Re: Alpha one shifting issue

Thanks Ziggy, that pic (and post) is worth a thousand words to someone who is doing this for the first time! I'm changing my impeller and lube and this is the thing I was wondering about. I did put it in fwd before I took the lower off so now I got the know how to do it right. Thanks!

nailem · May 17, 2008

Re: Alpha one shifting issue

i am having the same problem and have a similar thread going so im very interested. my boat shifted fine before the impeller replacement and after it clicks when in reverse. i adjusted my shift cables to compensate and it does shift fine now on land with muffs but im not sure why i had to adjust.

Mkos1980 · May 17, 2008

Re: Alpha one shifting issue

nailem said:
i am having the same problem and have a similar thread going so im very interested. my boat shifted fine before the impeller replacement and after it clicks when in reverse. i adjusted my shift cables to compensate and it does shift fine now on land with muffs but im not sure why i had to adjust.

Ditto!!

skunked · May 17, 2008

Re: Alpha one shifting issue

GREAT INFO!! I'll pull the lower and report back.

Thanks

skunked · May 17, 2008

Re: Alpha one shifting issue

Edit- Went back out in the gareg after a little break in the AC and little iced coffee and the lower slid right on.

After the drive was back on I looked behind the drive to make sure the shift lever as ziggy described above was in the correct location and found the problem I've had all along.....

here is a pic showing the issue (gap between shift shafts) and creating the shifting issues. I'm wondering what would cause this and what the solution would be.

Don S · May 17, 2008

Re: Alpha one shifting issue

I can tell you EXACTLY what's wrong. Someone forgot the SS washer that goes on the shift shaft above the rubber washer.
Here is the link to the OEM service manual, section 3B, look at page 3B-34.

http://www.boatfix.com/merc/Servmanl/6/6B3R3.PDF

skunked · May 17, 2008

Re: Alpha one shifting issue

Don S said:
I can tell you EXACTLY what's wrong. Someone forgot the SS washer that goes on the shift shaft above the rubber washer.
Here is the link to the OEM service manual, section 3B, look at page 3B-34.

http://www.boatfix.com/merc/Servmanl/6/6B3R3.PDF

SOB!!!

Your right Don, that washer is not there.

Well, off the local Merc dealer

sarantis · May 17, 2008

Re: Alpha one shifting issue

it's difficult to imagine which of those two (the shaft or the coupler)is in the wrong position.I think without dissasembling you can't do many things

Don S · May 17, 2008

Re: Alpha one shifting issue

sarantis said:
it's difficult to imagine which of those two (the shaft or the coupler)is in the wrong position.I think without dissasembling you can't do many things

Not hard to figure out at all. The upper shift shaft can't move up that far. But the lower shift shaft can go down that far.

Alpha one shifting issue

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