Help with identifying outdrive

[Brunswickbmech]

I have a 78' sea ray I am working on. I am replacing the motor (another subject all together) but I am starting with re-sealing the outdrive as it's a smaller unit. My lower unit appears to be an mc-1 or an R as it has the pre load pin on drive shaft. I believe due to the lack of a retaining ring under the water pump that makes it an mc-1. However my upper unit does not have the ridges made into the upper gear case as seen in the attached photo, nor does it have the loop on the upper gear case. I just want to make sure I know what each one is so I can order the correct parts, or even that the two units are compatible as I know some can be matched together. I will post pics of my actual units when I get home.

 

[Bt Doctur]

I`ll wager a guess it`s a MR unit

 

[achris]

You should be able to find a serial number somewhere on the housing. Anyway, R, MR and Alpha One all use the same seal kit.

Chris........

 

[Brunswickbmech]

Ok a worse update. No serial number to be found on upper casing on either side. I pulled the cover to take a look inside, and bam, chunks of broken gear. I was able to remover the chunks and turn the u-joint. It's the lower f@#%g spur gear. I counted the teeth, it's 16. Would it be cheaper to find another used upper unit, or buy a new gear set and replace the spur gears. And if it's cheaper for a used unit which one would fit my mc-1 lower unit. So mad right now. I didn't get home till after midnight so pics will have to wait till morning

 

[achris]

Regardless of the lower, any upper (MC1, R, MR, Alpha One) will fit. You just need to have the right ratio. And that brings us to another subject. The only ratio with a top box 16 tooth gear anywhere is a 1.32:1. What engine was is behind?

As for the cost.... Just buying the tools to set the gears up (and you can only buy the gears as a set, not individually) would cost more than a brand new SEI upper housing. Also, consider that the housings are linked by the oil passage. Any debris metal from the upper will have made its way into the lower, and will facilitate the lower housings eventual, and probably fairly soon, demise. I would seriously consider buy a complete drive.

HERE is a link to the ones iboats sell. 1.32:1 is no longer available, so move to the 1.47:1 and increase the prop pitch one size (2").

Chris..........