Unable to identify serial number - Mercruiser 5.7 V8 Thonderbolt

Danmarine

Cadet
Joined
Apr 2, 2022
Messages
29
Hello everyone.

I have a small problem with identifying the engine. Found the serial number which is on the plate, mounted on the side of the engine, above the starter motor. The number is: M023826

The engine is a V8 GM block. The following is written on the engine screen:
Model: MCM 5.7 Thunderbolt

However, I can't seem to find this number anywhere and therefore can't quite determine the model, year and which drive is on it. The drive has no series marking plates.

Maybe there is a sharp person in here who might know about this or know if there is a misreading of the serial number has occurred? :)

Have attached 2 pictures of the drive - maybe someone can determine the model from this?

I hope for your understanding and thank you in advance :)
 

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Scott06

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Apr 20, 2014
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5,671
That is an alpha one gen 2 drive serial number would be on left hand side of drive by vent plug but looks like it may have been painted over
 

Fun Times

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May 16, 2009
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8,809
0M023826 comes up as MERCRUISER 5.7L, Alpha, 3" RISERS, Model Number 4311035N1..
The year isn't as important but using the serial number is as Merc sort of stopped going by the year to find things. But a roundabout guess of the year will be 2001 - 2003ish... What year is the boat the engine is in?

 

Scott06

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Apr 20, 2014
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5,671
You have to put a 0 in front of the M .... my 0M 6xxxx serial engine is a june 2003 build. So you will have a 98 and up Gen two drive


Any parts in particular you are looking for ?
 

Danmarine

Cadet
Joined
Apr 2, 2022
Messages
29
Thank you very much for the help to all of you :=)
It's perfect!

I also think the mistake was that I could not see (or knew) that there should be a "0" in front of the M.

It is a customer who unfortunately has a Mercruiser 5.7 where the engine needs to be changed and therefore I was a bit interested in finding out the model in relation to a new engine, gaskets and spare parts.

The same would also apply to the drive.

In any case, a big thanks must go out to all of you for the quick and well-explained feedback. :=)
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
11,856
If you’re changing the engine you can also look for the GM casting # on the bellhousing that will tell you exactly what you have. To be 100% sure check the casting # of the cyl heads as well. There are charts on line that can de-code these #s for you. With an older boat unless it’s the original owner you never know what was done over the years.
 
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