Alpha One with prealpha lower? ID help

[pmill]

This is the outdrive on my used boat I bought a few months ago. First problem I ran into that confused me was replacing the impeller in this outdrive. I bought a complete kit (Alpha one Gen 1) and the base of the impellar kit didn't quite match up with the old one. The top half and gaskets were identical as far as I could tell and the base was in good shape so I just replaced the impeller and top half parts.

Now I'm changing out all the anodes and the kit I bought for alpha one gen 1 has a large anode for the trim manifold, but the manifold on this outdrive has no way to mount this anode.

According to this link everything except the lettering on the prop nut looks Alpha one to me, but not positive.

Do I have a prealpha gimbal housing and lower with an alpha one upper? Or the wrong trim manifold?

Thanks

 

[Fishermark]

Re: Alpha One with prealpha lower? ID help

Looks like you simply have a manifold that doesn't accept the anode. I guess you could replace the manifold... or simply go without.

Oh yeah - welcome aboard!

 

[Bondo]

Re: Alpha One with prealpha lower? ID help

View attachment 227295View attachment 227296View attachment 227297

This is the outdrive on my used boat I bought a few months ago. First problem I ran into that confused me was replacing the impeller in this outdrive. I bought a complete kit (Alpha one Gen 1) and the base of the impellar kit didn't quite match up with the old one. The top half and gaskets were identical as far as I could tell and the base was in good shape so I just replaced the impeller and top half parts.

Now I'm changing out all the anodes and the kit I bought for alpha one gen 1 has a large anode for the trim manifold, but the manifold on this outdrive has no way to mount this anode.

According to this link everything except the lettering on the prop nut looks Alpha one to me, but not positive.

Do I have a prealpha gimbal housing and lower with an alpha one upper? Or the wrong trim manifold?

Thanks

Ayuh,... It looks like an Alpha 1 drive,... The transom might be an MC-1, what vintage is the hull,..??

Best of My knowledge, that monster anode for the hyd. manifold appeared with the Alpha 1, Gen.II drives in '91,...

 

[thumpar]

Re: Alpha One with prealpha lower? ID help

The bellhousing is an older style so most likely the gimbal housing is also. If you are in fresh water I wouldn't worry about the extra anode. Did the lower have the preload pin or a groove for an o-ring on the shaft?

 

[Eric 3.7LX Alpha 1]

Re: Alpha One with prealpha lower? ID help

See the Alpha One and older MC 1 lower halves side by side. The Alpha One doesn't have the preload pin on top. They use the same impeller kit except the lower housing as you already know.

The Alpha One also has a squared off anti-ventilation plate where the MC 1 is more rounded at the corners.

They are interchangeable as a complete lower half, but not internal parts.

 

[ktbarrentine]

Re: Alpha One with prealpha lower? ID help

His anti-vent plate looks more like the Alpha-1. Quite the conundrum!

 

[thumpar]

Re: Alpha One with prealpha lower? ID help

Could be an R or MR lower.

 

[pmill]

Re: Alpha One with prealpha lower? ID help



The hull is an 89 and according to previous owner came factory with 4.3L that was swapped out for a 470 when the time came. There is a preload pin and o-ring on the shaft. The anti ventilation plate is definitely more square then rounded. Is it possible the housing itself is alpha but the gears and shaft are older style??

I thought about replacing the trim manifold with the newer style that accepts an anode, but looking at close up pictures to compare the two, theres a difference in shape on the threaded part that goes upside into the gimbal housing. This boat is 100% saltwater and theres signs of slight pitting on the lower that was painted over at some point. I've put another 40 hours or so on the ocean since I bought it and don't see any signs of new pitting, but it makes me curious if my configuration doesn't have that large anode if it would be worth it to find a way to install it.