Mercruiser Pre-Alpha (MC1) Broken Beyond Repair... Options/Recommendations?

[ToddCave]

Hello, all!
New user here to iBoats (sorta new... had an account a long time ago but forgot it so here I am again). And I have a repair options question.

I have an old outdrive that is corroded beyond repair; I tried to pull the bearing and a chunk cracked off, if that gives you any idea of what we're dealing with here. So I'm wondering what my best options are as far as either just buying a new outdrive of the same model or putting on a new outdrive, like a bravo or alpha or something.

Currently, I have a pre-alpha (MC-1). What would the wise folks here recommend doing, buying another MC1 somewhere or replacing what I have now with an Alpha? I've read that the gen1 is not a bolt-on replacement or anything but that it's doable. I would say I'm a moderately experienced DIYer. Not an expert by any means but I have most tools, and I'm comfortable doing home repairs/woodworking/replacing things like head gaskets on my cars, etc. Either way, I have two questions:

Question One: if I should just get another MC1, what are some good reputable shops (online)? How can I be sure that I'm getting the right parts with the right gear ratio, etc.?

Question Two: If I should put on a gen1 alpha, what am I looking at doing? It is more a matter of filling some holes and drilling others, or are we talking full transom replacement? Any guides (I didn't find any in the search) that will walk me through the process?

Thank you all in advance!!

 

[Eric 3.7LX Alpha 1]

What bearing did you try to pull? The gimbal bearing? Your easiest bet would be another MC-1 in better shape. What engine and or gear ratio do you have. I had a MC1 bolted to my Alpha One bellhousing for a few years as as a back up without any issues except for the length of the universal joint shaft length is different. The older is shorter and had to swap.

 

[Scott06]

Pretty sure except for possible driveshaft (into coupler) length difference any later R/MR/ Alpha gen one will bolt up.
you can get a used drive or look at the aftermarket SEI 106 drives. Says it fits 1972 -1990 which should cover your mc1

 

[achris]

Hello, all!

Hello ToddCave.

I have an old outdrive that is corroded beyond repair; I tried to pull the bearing and a chunk cracked off,

Which bearing? If it's one in the drive, no problem. If it was the gimbal bearing yeah, that's an issue.

I've read that the gen1 is not a bolt-on replacement or anything

Errrr yes, an Alpha One will bolt straight on. If you have an inline GM engine (2.5 litre/120 or 3 litre/140) then all you need to do is change the input yoke.

I have two questions:

Question One: if I should just get another MC1, what are some good reputable shops (online)? How can I be sure that I'm getting the right parts with the right gear ratio, etc.?

What engine do you have? The engine determines the ratio.

Question Two: If I should put on a gen1 alpha, what am I looking at doing? It is more a matter of filling some holes and drilling others, or are we talking full transom replacement? Any guides (I didn't find any in the search) that will walk me through the process?

If you're going to go the whole transom assembly replacement path, forget Gen 1, go straight to Gen II. The last gen 1 is now 30 years old (and any MC1 you get will be AT LEAST 40 years old!)... And transom cut out will depend on which MC1 you have (early, with no trim senders on the gimbal ring or later, with trim sender on the gimbal ring). At worst, you need to open the cutout up in the middle about 12mm and raise up the stud holes in that area about 25mm. The Gen II would also need a couple of 14mm holes drilled at the top. (I've posted a picture at the bottom)

Regardless (Gen 1 or Gen II) modifications to the transom are the easy part. You'll need to pull the engine and change the inner transom plate, and the engine flywheel cover. You will also need to drill the flywheel (very accurately!) and fit the new style coupler.

Chris.......

 

[nola mike]

Hello ToddCave.

Which bearing? If it's one in the drive, no problem. If it was the gimbal bearing yeah, that's an issue.

Errrr yes, an Alpha One will bolt straight on. If you have an inline GM engine (2.5 litre/120 or 3 litre/140) then all you need to do is change the input yoke.

What engine do you have? The engine determines the ratio.

If you're going to go the whole transom assembly replacement path, forget Gen 1, go straight to Gen II. The last gen 1 is now 30 years old (and any MC1 you get will be AT LEAST 40 years old!)... And transom cut out will depend on which MC1 you have (early, with no trim senders on the gimbal ring or later, with trim sender on the gimbal ring). At worst, you need to open the cutout up in the middle about 12mm and raise up the stud holes in that area about 25mm. The Gen II would also need a couple of 14mm holes drilled at the top. (I've posted a picture at the bottom)

Regardless (Gen 1 or Gen II) modifications to the transom are the easy part. You'll need to pull the engine and change the inner transom plate, and the engine flywheel cover. You will also need to drill the flywheel (very accurately!) and fit the new style coupler.

Chris.......

View attachment 348865

Why would the coupler need to be changed if the alpha bolts on? I think I remember the spline counts were different on some early drives (don't recall if that's yoke, gear housing drive shaft, both?). Is the later style transom plate/ gimbal housing a different thickness?

 

[achris]

Why would the coupler need to be changed if the alpha bolts on? I think I remember the spline counts were different on some early drives (don't recall if that's yoke, gear housing drive shaft, both?). Is the later style transom plate/ gimbal housing a different thickness?

The coupler is why the yoke changed length. (To match the rest of the product line)

 

[ToddCave]

thanks for the input everyone! To answer a common question, that gimbal bearing is the one that is corroded, and my bell housing isn't in great shape because of it.

Can I ask a clarifying question? Seems like there's some disagreement about whether or not an alpha gen 1 will bolt on. Am I understanding @achris properly that IF i do any kind of conversion (that is, go with anything other than another MC-1), I will have to pull the engine? I don't have the means (equipment or financial) to pull the engine, so I'll have to do a solution that doesn't require engine pulling.

If an Alpha Gen 1 just bolts right up to an MC-1 inner transom plate, even if I might need to buy a few extra parts for the conversion, I like that idea just because alpha gen1s are a little newer and I think parts should be a bit easier to find. Would I need to get an alpha gen 1 bell housing, or would I get another MC1 bell housing? Not exactly sure what people mean when they say it "bolts right up."

But if I'd have to pull the engine for anything other than a MC-1, I'll just get another MC-1 and make sure it's in good condition. Where should I be looking? How can I make sure that I'm buying from a reputable shop? Any suggestions for online resources/good salvage yards/etc?

Thanks all!!

 

[Scott06]

thanks for the input everyone! To answer a common question, that gimbal bearing is the one that is corroded, and my bell housing isn't in great shape because of it.

Can I ask a clarifying question? Seems like there's some disagreement about whether or not an alpha gen 1 will bolt on. Am I understanding @achris properly that IF i do any kind of conversion (that is, go with anything other than another MC-1), I will have to pull the engine? I don't have the means (equipment or financial) to pull the engine, so I'll have to do a solution that doesn't require engine pulling.

If an Alpha Gen 1 just bolts right up to an MC-1 inner transom plate, even if I might need to buy a few extra parts for the conversion, I like that idea just because alpha gen1s are a little newer and I think parts should be a bit easier to find. Would I need to get an alpha gen 1 bell housing, or would I get another MC1 bell housing? Not exactly sure what people mean when they say it "bolts right up."

But if I'd have to pull the engine for anything other than a MC-1, I'll just get another MC-1 and make sure it's in good condition. Where should I be looking? How can I make sure that I'm buying from a reputable shop? Any suggestions for online resources/good salvage yards/etc?

Thanks all!!

It might be worth posting some pictures of the damage you need to fix on your gimbal housing becuase if that is damaged your engine needs to come out either way to replace the gimbal housing.

An alpha one gen one will bolt up and work on your existing transom assembly if it is in good condition... If you have an inline motor (might help if you post your serial number) you will need to swap the shorter input shaft that goes in the coupler off your old MC1 drive. This is easily done at the ujoint.

 

[achris]

thanks for the input everyone! To answer a common question, that gimbal bearing is the one that is corroded, and my bell housing isn't in great shape because of it.

Can I ask a clarifying question? Seems like there's some disagreement about whether or not an alpha gen 1 will bolt on. Am I understanding @achris properly that IF i do any kind of conversion (that is, go with anything other than another MC-1), I will have to pull the engine? I don't have the means (equipment or financial) to pull the engine, so I'll have to do a solution that doesn't require engine pulling.

If an Alpha Gen 1 just bolts right up to an MC-1 inner transom plate, even if I might need to buy a few extra parts for the conversion, I like that idea just because alpha gen1s are a little newer and I think parts should be a bit easier to find. Would I need to get an alpha gen 1 bell housing, or would I get another MC1 bell housing? Not exactly sure what people mean when they say it "bolts right up."

But if I'd have to pull the engine for anything other than a MC-1, I'll just get another MC-1 and make sure it's in good condition. Where should I be looking? How can I make sure that I'm buying from a reputable shop? Any suggestions for online resources/good salvage yards/etc?

Thanks all!!

2 things.
1. Replacing the gimbal housing, whether it be with a direct replacement MC1 or an Alpha One (either generation) will require pulling the engine. It is not possible in any way to avoid that.
2. Apart from the same MC1 gimbal housing, you will also require to fit a matching inner transom plate. MC1 inner will not fit on an Alpha One gimbal housing...

Chris...

 

[ToddCave]

It might be worth posting some pictures of the damage you need to fix on your gimbal housing becuase if that is damaged your engine needs to come out either way to replace the gimbal housing.

An alpha one gen one will bolt up and work on your existing transom assembly if it is in good condition... If you have an inline motor (might help if you post your serial number) you will need to swap the shorter input shaft that goes in the coupler off your old MC1 drive. This is easily done at the ujoint.

Oh... I didn't realize that I would have to pull the engine even just to replace the bell housing with the same bell housing I have now. Don't you need pretty specialized equipment to pull the engine? How much might I be looking at to get something like that done (money-wise)?

Thanks

 

[Scott Danforth]

Oh... I didn't realize that I would have to pull the engine even just to replace the bell housing with the same bell housing I have now. Don't you need pretty specialized equipment to pull the engine? How much might I be looking at to get something like that done (money-wise)?

Thanks

basic hand tools and a hoist

a 6-pack of beer helps

 

[Eric 3.7LX Alpha 1]

You don't have to for the bellhousing, you do for the gimbal housing..which end of the bellows has the corrision? the bellhousing end or the gimbal housing end?

 

[ToddCave]

I'm sorry, yes, I wasn't thinking. It's the gimbal housing end... the bearing was so rusted/corroded in there that it took some chunks out on the way out. I just figured I could bolt on a new gimbal housing pretty easily, I didn't know that I would need to pull the engine to replace that gimbal housing. Yikes.

Thanks

 

[Scott Danforth]

pulling the motor is easy

it also allows you to clean the bilge

 

[achris]

... I just figured I could bolt on a new gimbal housing pretty easily,...

You can, once the engine's out of the way.

 

[ToddCave]

hm.. okay.. thanks for all that input. So then, another question. If I have to pull the engine basically no matter what, what's my best option given that I'll have a MC-1 shaped hole in my transom? It feels like that opens the door for basically any option... I could replace with any outdrive that works with my motor (GM inline 6), right? Or is this the point when people usually just take the loss and sell their boat, because it's not worth the hassle of doing this anymore? Or I guess I could even think about an outboard bracket or a conversion or something at that point. What would you recommend?
Thanks!!

 

[achris]

What I'd do....

Option 1. Find an old rotted out Bayliner with a 3litre engine of about 1995 and later (and one with a freeze damaged engine may even be a giveaway). Pull the engine out and take the flywheel housing and coupler off, the trim pump assembly, and the shift cable plate, and sell the rest off (once you have finished the job, not before!) Take the gimbal housing, inner transom plate and drive and put them on your boat (you'll also need to change prop pitch for the higher drive ratio. The 160/165 had 1.65:1 and the 3 litre runs a 1.94:1). Drill you existing flywheel to fit the new coupler, change the flywheel housing and you should be good to go.

Option 2. Find a good 4.3 litre engine, gimbal and inner plate, and drive (again, 1995 and later) and do a complete transplant.

The first option will be the cheapest, but involves the most work, and you'll still be left with an engine more than 40 years old.
If you can afford it, and there's room in the boat for the extra width of the v engine, that's the better option, imo.

In my opinion, an outboard bracket on boat designed for a stern drive engine very rarely works properly. I was a MerCruiser dealer for quite a few years, and I didn't have a single customer who was as happy with his boat with a bracket was he was with the stern drive... When you add the expense of the bracket and the engine, is by far the most expensive option... (Cue the haters)

Chris...

 

[Scott Danforth]

(Que the haters)

LMAO and blowing beer out my nose

 

[ToddCave]

hm. So just to give me a super ballpark idea of what's in store... what might I be looking at as far as cost for something like a full transplant at a shop? I don't have the gear to pull and engine (don't have a hoist or anything) and don't trust myself to do it right.

Thanks!!

 

[Scott Danforth]

hm. So just to give me a super ballpark idea of what's in store... what might I be looking at as far as cost for something like a full transplant at a shop? I don't have the gear to pull and engine (don't have a hoist or anything) and don't trust myself to do it right.

Thanks!!

Shops wont swap used parts. Most will only swap in brand new

If you find a shop, expect $125 per hour or more