Alpha one drive issue diagnosis

[the man]

2005 4.3L Mercruiser with an Alhpa one outdrive. Closed cooling, 190 hp, TKS. Engine serial # OW311876. Drive OW562120. Note: on the engine, it says Nov 2004 production.

Symptoms in water: In forward, engine stalls as soon as it is put into gear. In reverse, engine will rev up. Neither direction will spin the prop.

Symptoms in shop: In forward, I can spin the prop shaft with a little resistance ccw, and it ratchets cw. In reverse, just the opposite. With use of a remote inspection camera I can see that when I turn the prop shaft, the drive shaft is not turning in the coupler.

So I deduct that gear shift including cable is working and the coupler is probably not the issue.

Agree? And what next? Thanks

 

[HT32BSX115]

Re: Alpha one drive issue diagnosis

Howdy,


If you're absolutely sure that the drive shaft yoke is NOT turning in the coupler it could be the prop hub.

Hearing the clicking (CW in FWD/CCW in REV) and "ratcheting " when you turn it CW/FWD & CCW/REV, makes me think that the cutch dogs are indeed locking together.

It makes me think that something else is busted inside.

Otherwise, you probably have a severely screwed up lower shift cable.....


You might want to drop the "lower" unit and try what you did before. turn the vertical drive shaft and place the drive in FWD/REV and see what happens.

This sounds more like coupler/prop hub slipping though.



Regards,


Rick

 

[the man]

Re: Alpha one drive issue diagnosis

Howdy,

Otherwise, you probably have a severely screwed up lower shift cable.....

The prop is not on the shaft. I am having that rebuilt. And I can see that the drive shaft is not turning in the coupler. I will pull the drive tomorrow and see what I can deduct.

When you say seriously screwed up, doesnt that fact that the ratcheting changes direction with shifting the control's prove that the shift cable is functional?

 

[HT32BSX115]

Re: Alpha one drive issue diagnosis

When you say seriously screwed up, doesnt that fact that the ratcheting changes direction with shifting the control's prove that the shift cable is functional?

I should have SAID seriously screwed up drive.


If the shift cable is actually shifting the drive, (the shift dogs are in the "lower") Then something else is "not right" internally.

does it turn the shaft when you start it on "muffs"?

 

[twostroke87]

Re: Alpha one drive issue diagnosis

2005 4.3L Mercruiser with an Alhpa one outdrive. Closed cooling, 190 hp, TKS. Engine serial # OW311876. Drive OW388117. Note: on the engine, it says Nov 2004 production.

Symptoms in water: In forward, engine stalls as soon as it is put into gear. In reverse, engine will rev up. Neither direction will spin the prop.

Symptoms in shop: In forward, I can spin the prop shaft with a little resistance ccw, and it ratchets cw. In reverse, just the opposite. With use of a remote inspection camera I can see that when I turn the prop shaft, the drive shaft is not turning in the coupler.

So I deduct that gear shift including cable is working and the coupler is probably not the issue.

Agree? And what next? Thanks

When out of the water and in the forward gear, a standard rotation alpha drive, when properly installed and functioning, should LOCKED when you try to spin it in the CCW direction, and ratchet in the clockwise direction.

The locked position of the drive shaft, if you are HE-MAN, and you forced it to turn CCW while it was in forward, you would be turning the entire engine. The opposite stands for reverse as well.

It really sounds to me like either your lower unit is shot (where the actual shifting takes place)

More likely it feels as if the drive was installed improperly, like the lever that is in between the forks on the shift slide, is not in the proper position.

 

[the man]

Re: Alpha one drive issue diagnosis

When out of the water and in the forward gear, a standard rotation alpha drive, when properly installed and functioning, should LOCKED when you try to spin it in the CCW direction, and ratchet in the clockwise direction.

The locked position of the drive shaft, if you are HE-MAN, and you forced it to turn CCW while it was in forward, you would be turning the entire engine. The opposite stands for reverse as well.

It really sounds to me like either your lower unit is shot (where the actual shifting takes place)

More likely it feels as if the drive was installed improperly, like the lever that is in between the forks on the shift slide, is not in the proper position.

Well I certainly am not turning the entire engine. I was kind of psyched when I figured it wasn't the coupler; now I wish it was! I will post what I find- but i also will probably be posting asking how to fix whatever I find...

 

[NHGuy]

Re: Alpha one drive issue diagnosis

On a gen 1 (I assume gen 2 may be same) forward gear is when the shift cable is pushed in, try to have someone push on the cable to see if you can get it into forward. When in forward the prop won't go backward, but will ratchet forward. If this engages your gears check your cable alignment or condition. It is possible the cable is balky and causing the electric shift-interrupter to stay engaged thus killing the engine.

 

[nuboat2me]

Re: Alpha one drive issue diagnosis

Recently having the same issue with my Alpha1, I changed out the lower shift cable and it fixed the issue. It took some tweeking to get FnR all dialed it but its working and thats all I wanna say about that....


good luck!!

 

[the man]

Re: Alpha one drive issue diagnosis

Pulled outdrive. Using shift lever on front of unit and turning the prop shaft, I can feel the gears engage and get the ratcheting in the correct directions. Turning the prop shaft ccw when in forward (shift lever pointing forward) the drive shaft does not turn. Bummer!

 

[NHGuy]

Re: Alpha one drive issue diagnosis

Put it in forward and try turning the drive from the yoke at the input end. Hopefully the prop turns. Then put the shift into reverse and turn the yoke the same way to check reverse.
If you still get no connection you can split the upper and lower sections to determine where the problem lies. If you haven't done this yet you can find videos of how to do it on you tube, etc. It's what you do to change the impeller.
At this point it sounds like you have upper gear case trouble. Someone with more experience than me may come along and recommend you pull the upper gearcase cover to inspect. I'm not sure if that is the right move.

 

[the man]

Re: Alpha one drive issue diagnosis

Pulled cap off and obviously found the problem. (see pic) Drive gear assembly is chewed to pieces. One immediate question- isn't this area supposed to be filled with oil? I have a gear lube monitor that I keep topped off.

I have the manual- but how hard is this to fix? Looks like I need some specialized tools.

 

[Fishermark]

Re: Alpha one drive issue diagnosis

how hard is this to fix?

The good news? Very easy to fix! It's called - "Buy a new outdrive."

Seriously, it will be cheaper to buy a complete aftermarket outdrive from Sterndrive Engineering than it would be to rebuild what you have.

 

[HT32BSX115]

Re: Alpha one drive issue diagnosis

One immediate question- isn't this area supposed to be filled with oil?

Yes.

Either the drive was ran low on oil, it leaked out or it was drained and refilled incorrectly.

The drive must be rebuilt or replaced.

You can't just replace the upper or upper gears and call it good. The whole mess must be disassembled and rebuilt.

You might look into getting a new SEI drive. It may cost less than rebuilding yours.


Sorry about that,


Rick

 

[NHGuy]

Re: Alpha one drive issue diagnosis

I think you can't just get an upper because it shares oil with the lower and the lower will be full of shrapnel. Get a drive, sorry guy.

 

[the man]

Re: Alpha one drive issue diagnosis

Yes.

Either the drive was ran low on oil, it leaked out or it was drained and refilled incorrectly.

Rick

How is it "filled incorrectly"? I recently had an "outdrive service" that I paid for. Any way to prove anything?

 

[the man]

Re: Alpha one drive issue diagnosis

it will be cheaper to buy a complete aftermarket outdrive from Sterndrive Engineering than it would be to rebuild what you have.

How do I tell what gear ratio I currently have? Kind of hard to count teeth at this point.

 

[HT32BSX115]

Re: Alpha one drive issue diagnosis

How is it "filled incorrectly"? I recently had an "outdrive service" that I paid for. Any way to prove anything?

When you fill a Mercruiser outdrive, it's filled from the bottom until oil flows out of the upper vent opening.

You might take a look at your invoice and see if it included a draining and refill.

ANYONE that does this for a living would know how to fill it. ......well, they should........

But I had a King Cobra that a DEALER did a drain and refill on.......and (didn't bother to refill)...... and it COMPLETELY destroyed the drive. They replaced it promptly with NO lawyering-up......

Another shop another year drained and refilled the drive (incorrectly) causing complete destruction and THEY replaced the drive too......It does happen.....

It's possible that you had a leak. How much time elapsed between the service and when you ran it last?

"Outdrive Service" wouldn't necessarily catch that problem....

If the upper gears were completely uncovered, it would only take one trip around the lake to permanently damage/destroy them.... In my case the boat didn't even make it all the way around the lake!!

 

[Howard Sterndrive]

Re: Alpha one drive issue diagnosis

How do I tell what gear ratio I currently have? Kind of hard to count teeth at this point.

call SEI - they'll tell you what ratio you need.

 

[the man]

Re: Alpha one drive issue diagnosis

Seriously, it will be cheaper to buy a complete aftermarket outdrive from Sterndrive Engineering than it would be to rebuild what you have.

What if I value my time at near zero (unemployed these days) and figure that I will learn alot doing this rebuild. Still say that is is cheaper?

I like what I read about the SEI drives- just wondering from a strictly financial, parts only perspective.

 

[Bt Doctur]

Re: Alpha one drive issue diagnosis

There are quite a few special tools needed.Some can be made but some need to be bought .
http://www.boatfix.com/merc/Tools/tool1.pdf

new gearset w/ bearings ,seals,O rings $500
water pump kit $60
2 qts of gear oil $XX
Misc $40
NO WARRANTY ________________
$600
Assuming NO damage in the lower unit
-----------------------------------------------------------------------------------------
SEI 116 3 year Warranty $695.00