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Stern Drive Repair

T

the-menace

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Hi Out there. I have a question about my stern drive. I am a novice of sorts and do not have an abundance of material on my 1984 MCM470. How can I know what stern drive is on my boat? Is it an Alpha One, or what? Is there anywhere on the outdrive or another place where it actually tells what drive is on my boat? I want to replace my transom sealing parts as I have a broken exhaust bellows and who knows what else? I want to buy a kit but am not sure which one to buy and certainly do not want to buy the wrong one. Thanks for any help I can get. Dennis aka The-menace
 
you most likely have the alpha 1 drive . the ratio is 1.84 in most cases. the top back of drive should have serial # stamped in the plate .

my 1979 mcm 470 has the r drive same ratio as the alpha 1. parts are very similar.

since your not replacing any gears in the drive this should not be any problem . bellows /bell housing parts/ shift cable/bellows/ gimble bearing /pivot studs should be same. use the engine serial number this is used just in case changes were made .top of valve cover.

have the engine alignment done with the drive removed .

use this chart :http://www.seilermarine.com/info/mercruiser-drive-ratio-chart.htm
 
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Thanks for all the help. I think I have it going now. I found that on the sites supplied by you two folks that my MR is nearly the same as the Alpha One, just a little older and most of the parts that I will need are basically the same. I was really getting confused with the Alpha One Gen I and Gen II. Thanks again. Dennis
 
I don't think I trust that chart! The 470 is definitely not a 4.3L motor it's 3.7L/224ci 4 cyl. And I don't believe the 165 is a 6 banger 3.7L/224ci motor either it's either a 3.7 4 banger (470 block) or a 250 ci I6 cyl. I don't believe they made the 6 cyl version into the 80's but correct me if I'm worng. That chart is full of holes.
 
the engine size is wrong but the drive info is correct. all the 470 engines are 224cu in. drive types did change 1984 and up .
 
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