Transom Assembly question

[Rangerboat26]

Hi everyone, need a little help, I got a 79 Sea Ray Express cruiser. I'm replacing the transom this spring and plan on putting on a new/used transom assembly it just makes too much sense with how shot my current one is and given the repair I'm doing anyhow. However what I understand a 79 boat should have a pre-alpha set up. My outdrive is definitely an alpha one, but I don't know if the transom assembly (gimbal housing) is pre-alpha or not the serial number is 5238134 or 5238434 (5th digit is a little scarred up hard to tell if its a 1 or 4). If it is pre-alpha I would like to go to an alpha, (83 and up). If i do this is it hard to convert? Not worried about different mount spacing since im doing transom work anyhow mostly concerned about the steering. Also I understand don't the pre-alphas have the tilt/trim lines through the transom? instead of mounted underneath the gimbal housing outside of the hull? If thats the big distinction then I lucked out and got a alpha as well. Just wanna know so I don't shop and buy the wrong one. Thanks

 

[Don S]

Re: Transom Assembly question

Number 1, there is no such thing as a Pre Alpha. That is just aftermarket slang for "We have no clue what the real name is"

The serial numbers you posted are too old to look up what exact engine they went too, but they do fall in the range of the 78 to 82 MC-1 Gimbal housing.

There is a lot of serial number and ID info here http://forums.iboats.com/mercruiser...cellaneous-mercruiser-information-329915.html

I would like to go to an alpha, (83 and up)

All 83 and up drives are not Alphas, 83 and 84 were the R. 85 was the MR, and finally in 86 we get the Alpha I.

 

[HT32BSX115]

Re: Transom Assembly question

Number 1, there is no such thing as a Pre Alpha. That is just aftermarket slang for "We have no clue what the real name is"

The serial numbers you posted are too old to look up what exact engine they went too, but they do fall in the range of the 78 to 82 MC-1 Gimbal housing.

There is a lot of serial number and ID info here http://forums.iboats.com/mercruiser...cellaneous-mercruiser-information-329915.html



All 83 and up drives are not Alphas, 83 and 84 were the R. 85 was the MR, and finally in 86 we get the Alpha I.

It also might be nice to know what year the bolt pattern became "standard" (across the Bravo/Alpha/VP-SX/Cobra drives)

Did that happen with the 86 (Mercruiser) models too? I know my old MC-1 was not the "same" as a newer Alpha model..........

 

[Bondo]

Re: Transom Assembly question

It also might be nice to know what year the bolt pattern became "standard" (across the Bravo/Alpha/VP-SX/Cobra drives)

Did that happen with the 86 (Mercruiser) models too? I know my old MC-1 was not the "same" as a newer Alpha model..........

Ayuh,... In 1991 I believe, with the intro of the Gen.IIs....

Previously, it was the same, less the two top bolt holes, since '73/ '74 or so...

Prior to that, the top 'n center bolt holes were slightly closer together...

 

[Don S]

Re: Transom Assembly question

The cutout changed a little from the 73 to 74 model. Cutout was larger at the bottom for the 74. Thee bolt pattern probably changed at the same time. Since then the basic pattern and cutout have been the same, except for the extra top bolts.
The two extra holes at the top, started with the Alpha I Gen II and on.
Bravo has always used the Alpha cutout since the beginning, both with and without the top 2 extra holes.
OMC used the pattern in 86 with the start of the Cobra drive, and Volvo started in 94 with the SX without the extra top 2 bolts.
Volvo used the top two with the big block engines.

Now, back to the original posters questions please.

 

[Bondo]

Re: Transom Assembly question

Hi everyone, need a little help, I got a 79 Sea Ray Express cruiser. I'm replacing the transom this spring and plan on putting on a new/used transom assembly it just makes too much sense with how shot my current one is and given the repair I'm doing anyhow. However what I understand a 79 boat should have a pre-alpha set up. My outdrive is definitely an alpha one, but I don't know if the transom assembly (gimbal housing) is pre-alpha or not the serial number is 5238134 or 5238434 (5th digit is a little scarred up hard to tell if its a 1 or 4). If it is pre-alpha I would like to go to an alpha, (83 and up). If i do this is it hard to convert? Not worried about different mount spacing since im doing transom work anyhow mostly concerned about the steering. Also I understand don't the pre-alphas have the tilt/trim lines through the transom? instead of mounted underneath the gimbal housing outside of the hull? If thats the big distinction then I lucked out and got a alpha as well. Just wanna know so I don't shop and buy the wrong one. Thanks

Ayuh,.... You have an MC-1, 'n an Alpha 1 transom assembly will bolt right in, 'n hook up, No problem...

'n Nope, the hyd. manifold was used on the MC-1s too...

Now, back to the original posters questions please.

Yes Dad, sorry I wandered off topic,....

 

[haulnazz15]

Re: Transom Assembly question

My first question is what do you mean by "how shot my current one is"? Are you talking about the inside transom assembly? The gimbal ring/bell housing? The drive itself?

As far as the trim lines, your trim lines should run up through the bottom of the gimbal housing just like the Alpha I's do. The really early drives had the trim go straight through the transom wall, but a '78-79 boat shouldn't be that way. If you are talking about just replacing the drive itself, it will bolt right up to the existing MC-1 bell-housing without modification. No real reason to swap to Alpha I that I can think of.

 

[achris]

Re: Transom Assembly question

Ayuh,.... You have an MC-1, 'n an Alpha 1 transom assembly will bolt right in, 'n hook up, No problem...

'n Nope, the hyd. manifold was used on the MC-1s too...

Bondo has that part right.... HOWEVER, your old style (1979) engine flywheel cover will not mount up to the Alpha inner transom plate.

 

[Rangerboat26]

Re: Transom Assembly question

Thank you everyone for the speedy response, I learned a lot in just that short thread. To sum up everyone's questions.... It is definitely looking like I most likely have an MC-1 as far as the transom assembly goes. When I say its shot I mean.... let me put it this way when I'm towing the boat down the road that outdrive is slappin around all over the place left to right, right to left, that's how much play there is in the steering. So I'm looking at gimbal ring/pins as far as repair goes, but through my research for what I'd spend in parts and labor, and doing it my self looks like a complete pain in the rear, I'd rather swap out the whole assembly. Especially since its going to be off to fix the transom anyway. I at first started pricing some new ones which is where I got the "83 and up" from on the michigan motorz website. All their description says is "Alpha I gen I, 83-1990". When I look at used, which is most likely what I am going to do all i get is the "pre-alpha slang" and alpha I for the description. As far as my outdrive itself goes its perfectly fine and I am going to reuse it, may upgrade to something from sterndrive engineering later on down the road....no matter what Im looking to keep a alpha gen I setup though and for the most part it looks pretty compatible as long as I don't go to gen II or bravo. So my main question is as far as the transom assembly goes, what kind of road blocks might I run into if I don't have an MC-1 assembly? Mostly as far as where the engine meets the transom plate? Do I need a different flywheel housing? Different steering linkages? Coupler? How different is the cutout in the transom itself?......etc.

 

[Rangerboat26]

Re: Transom Assembly question

Also, engine is a remanufactured 83 gm block, mercruiser 260 replacement, not my choice was supposed to be a 79 block but the remanufacturer screwed up and sent me the wrong engine! Runs fine though and all the old parts matched up minus dipstick and oil pan. So it has the original flywheel, housing, and coupler

 

[Rangerboat26]

Re: Transom Assembly question

Wait a sec....after reading through everyone's post a little more thoroughly, according to bondo, as long as its the MC-1 no prob putting in a Alpha 1? with the exception of maybe changing the flywheel housing? Is that it in a nutshell?........if thats the case consider my questions answered!

 

[Don S]

Re: Transom Assembly question

As long as you can hook your exhaust Y to the newer gimbal housing, it shouldn't be a problem. The cutout and bolt pattern Will NOT be a problem.

 

[HT32BSX115]

Re: Transom Assembly question

Yes Dad, sorry I wandered off topic,....

We do that sometimes!:lol: