Spotted a 1 crack in my outdrive Alpha 1 Gen2-gctid377667

[Guest]

Hello all, heres a pic of what Im talking about, reasons to be concerned????????

Thanks

Mike

Attached files [img]/media/kunena/attachments/vb/681122=27212-IMAG0350.jpg[/img]

[MidnightSun]

I would get it welded and call it a day.

[2850Bounty]

I agree with Hans! This is at the exterior of the prop shaft bearing carrier, and AFT of the portion where the gears/bearings/oil is.

You'd have to go forward quite a bit in order to get into the gears/bearings/oil.

Attached files [img]/media/kunena/attachments/vb/681136=27213-Merc propshaft brg carrier.jpg[/img]

[TerryW]

That looks like an underwater shot. I guess it isn't.

Any idea what caused it? or was that the point of the question?

I'd get it professionally welded and strengthened if there are no other suspicious areas of corrosion and/or cracks.

My alpha 1 gen 2 has a 1" x 2" hole caused by corrosion where the exhaust bellows connects onto the gimball housing. The unit is still in frequent use. That will be a weld-up job at the end of the season. The reason I mention this is that I don't regard the outdrive as a sculpture (although it isn't ugly), it is just a rough bit of agricultural kit that can be welded and otherwise bashed back into service when the need arises. I don't mean by that that repairs can be amateurish I am just saying that there is little need for concern if repairs of this nature are called from. They get a very hard life (well mine does anyay).

Terry

[itsabowtime2]

As others have said, get it welded and call it a day. You do not want it to get any larger.

[2850Bounty]

TerryW wrote:
That looks like an underwater shot.

It does, doesn't it? I hadn't thought of that until you mentioned it.

Perhaps the CSI Miami crime lab division did the lighting for forensic evaluation! Never know!

As for welding this crack.... don't be surprised if the material is so contaminated that it cannot be TIG'd.

Aluminum is very fussy re; this!

[Vic_Stewart]

Looks to me like some serious corrosion. There is no reason for that section to fatigue and break like it did. Welding contaminated aluminum is mostly a waste of time, it will litterally 'explode' and look very ugly when done. As far as the crack goes..that section is machined to specs for the carrier, the crack violates the specs and the carrier will never fit right.

I would, if it were mine, trash the lower section and get a new one.

Just my 2 cents worth

Vic

Ft Myers, Fl

[2850Bounty]

Vic makes a very good point!

I have my suspicions as to what may have caused this.

The Merc A drives have had issues in this area for years when in salt water.

The aft most locking ring threaded area is prone to corrosion issues. Often these are so stubborn that they need to be broken up in order to remove them.

If corrosion was to cause the aluminum to expand at the threaded area, it's possible that enough pressure from this expanding corrosion simply expanded and broke the housing.

It's a rather moot point... but perhaps explains what caused this.

It may have been caused from a prop impact as well.

His internals could also be installed into another housing.

What does a new SEI lower unit cost?

Can you purchae an SEI lower unit only?

[itsabowtime2]

SEI lower 1/2 is less than $900.

[TerryW]

You might want to look at http://www.stern-drive.com/gear-case.../Alpha-One.htm

I had a new bottom unit from the above. It is perfectly functional, looks good, was an easy swap and is nicely finished. I haven't had it for very long so I can't speak of their longevity. Downside it is noisier than the original at low speed. It grinds along like an old tractor gearbox. Does that matter a whole load? not really as long as it doesn't fail. But then there is the guarantee. Over here in the UK, it was at least 1/3rd cheaper than the factory model.

Good luck.

[Guest]

I have seen this a lot, Bravo's will do the same thing. It usually happens in salt water where there is more corrosion. Boats that sit in the water for long periods of time without putting them in gear and spinning the props get a build up crud and corrosion between the inner hub of the prop and the inside of the outer gear case where the prop fits inside. It gets stuck or sticky from the build up and cracks when you put it in gear and spin it. Both of my Bravo 2's are cracked like this. It happens a lot to dock queens that don't get much use.

Thunder

[Guest]

Sorry for not getting back earlier guys, been away for a bit. Not an underwater shot, had me camera set to incandescent for some unknown reason. Last season some idiot placed a very large block od concrete too close to my swing mooring and as a result in low tide the outdrive started belting against it, breaking the fin anode above this area and lightly bending the prop.

Will try a weld, nothing to lose at this stage. I just hope it has nothing to do with my spun prop symptoms.

Thanks

Mike

[Guest]

If you end up choosing not to weld, drill a hole at the end of the crack. A crack will continue to crack further unless the stress is released somehow. This is what drilling at the end of the crack does. Ask me how I know (Alpha I with 1 inch crack! It seems no worse for the crack though).

Chay

[bhawes]

You should remove your prop and check the shaft for runout. If the banging about, and a damaged prop, caused this, it may have also bent you're shaft. This WILL take out the rear seal and shortly afterwards take out your entire outdrive (as the lube seaps out, and the saltwater in).

[Guest]

Cheers guys, how do I check for run out Bob?

Rgds

Mike