Is it an apha one lower unit if it does not have preload pin

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phil rogers

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I have a 77 mercruiser 140 upper seriel no is 444065.Is it for sure an alpha one lower unit if it has no preload pin? thanks phil:confused:
 
Bondo

Bondo

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Re: Is it an apha one lower unit if it does not have preload pin

Is it for sure an alpha one lower unit if it has no preload pin?
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Ayuh,... Unless somebody Broke it Off,...
 
JustJason

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Re: Is it an apha one lower unit if it does not have preload pin

Is it for sure an alpha one lower unit if it has no preload pin? thanks phil
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No it is an "R" drive. Everything "R" and earlier is a "pre-alpha" But that term only came about in the mid 80's when the "MR" (Mercruiser revised) came about.
 
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rodbolt

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Re: Is it an apha one lower unit if it does not have preload pin

unless the lower was replaced.
the MR had no preload the R did and the two can be swapped as a unit.
about the only way I can remember to positivly ID them is to look at the drive shaft or the upper bearing in the lower case.
 
JustJason

JustJason

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Re: Is it an apha one lower unit if it does not have preload pin

is the back of the anti ventilation plate rounded or square?
 
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phil rogers

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Re: Is it an apha one lower unit if it does not have preload pin

I have found out that it is either an mr or alpha one but I think it is mr.The reason I was trying so hard to find what unit I have is the lower unit has been full of water since I put water pump on last year.I put an r lower water pump assembly.Could this be why I have water in lower unit.I havent had boat too long and had not checked it before it got hot last year. thanks phil
 
JustJason

JustJason

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Re: Is it an apha one lower unit if it does not have preload pin

The "R" and the "MR" use 2 different water pumps.
 
ziggy

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Re: Is it an apha one lower unit if it does not have preload pin

I put an r lower water pump assembly.
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don't know if this answers your question. but, the water pump kits i've been getting at my mercruiser dealer have all said fit my 1 drive through alpha1...
 
JustJason

JustJason

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Re: Is it an apha one lower unit if it does not have preload pin

don't know if this answers your question. but, the water pump kits i've been getting at my mercruiser dealer have all said fit my 1 drive through alpha1...
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Ack Ziggy!?!?!? I just looked and I got 2 different part ##'s. It's late... figure it out tomorrow.
 
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