Why Alpha1 G2 aluminum transom bolts?

[Rick Stephens]

Trying to figure this out. Swapping out an Alpha1 to a GenII. Bottom bolts on the Alpha 1 transom plate to gimbal housing are steel. On the GenII the bottom bolts are aluminum carriage bolts with a itsy bitsy rubber washer to keep water out of your transom.

On donor boat those aluminum bolts were pitted and corroded and one of them, when trying to unscrew the nylock nut, broke the bolt very easy. Makes me think this is some sort of shear bolt to protect the transom plate if you hit something?

In the first photo you can see the new OEM bolt from Merc alongside the pulled bolts. Left hand bolt has the little rubber washer on it. I'd like to know if one should fill the bolt hole with 4200 or similar to keep water from intruding past that chintzy rubber gasket.

Appreciate the thoughts.

 

[alldodge]

Looks like you have a first generation Gen II housing, later models went away from the bolts on the bottom.
http://www.mercruiserparts.com/Show...32.png&inbr=1017&bnbr=30&bdesc=Gimbal+Housing

Aluminum bots sure make me scratch my head, I sure wouldn't have thought they would be aluminum. If Chris (achris) doesn't come in and answer the question I would PM him and have him come take a look at this thread

 

[Fishermark]

...Bottom bolts on the Alpha 1 transom plate to gimbal housing are steel. ...

It sounds to me like someone swapped them out. The original bolts would have been aluminum (or similar alloy) with a stud on the end for a zinc.

 

[Rick Stephens]

AllDodge, indeed, the Gen2 is a '93, ser 0D648864. It has the square carriage bolt holes for the bottom 2 bolts in the gimbal housing.

Thanks for the clue on the Alpha1 Fishermark, I had no idea. Never pulled a transom before. The Alpha1 has the zincs, not sure how they accomplished the steel studs. I'm not too worried about what bolts are on it since it is getting parted out. I was surprised by the aluminum bolts in the Gen2, those and the little rubber washer seem insufficient to the task of keeping water out of the transom and corrosion away from the aluminum bottom bolts. I wonder how many salt water Gen2's are rotting out because of those aluminum bolts?

Rick

 

[Bondo]

I wonder how many salt water Gen2's are rotting out because of those aluminum bolts?

Donno, but those aluminum bolts have been used on the bottom of the transom assembly's since atleast the early '70s,....

 

[Rick Stephens]

Donno, but those aluminum bolts have been used on the bottom of the transom assembly's since atleast the early '70s,....

See any reason they couldn't be sealed in with 4200?

 

[Fishermark]

The rubber gasket does a fine job of sealing the bolts. The reason they end up leaking is because the transom typically gets rotten and they become loose. I wouldn't go crazy with the sealer. A dab should be fine.

 

[produceguy]

My gen 1 has aluminum bolts also. I broke the head off when removeing them. I didnt use any sealent on the new anode bolts at all. Seems to be fine.

 

[produceguy]

I looked it up on some other forums and yes, you should use sealent.

 

[Rick Stephens]

Thanks for the thoughts produce... I like your restoration thread. Lot to learn there.