Differential numbers

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Dec 31, 2023 | 03:43 PM

kansas123

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Melting Slicks

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From: Wichita Kansas

Differential numbers

I located these on the bottom of my diff, wonder if they are enough to tell anything about it. On a '72 350 automatic. Thanks

(PS, might be missing some) AW 116 E12

Will do some more googlin' in the meantime

Dec 31, 2023 | 04:03 PM

n2h2o2

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From: Smyrna, TN

AW = 3.08
116 = day of the year (April 25)
E= Eaton plant
12= should be the shift so maybe this was built on both 1st and 2nd shift?

Dec 31, 2023 | 04:24 PM

kansas123

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Melting Slicks

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From: Wichita Kansas

I really really REALLY appreciate that information Nitrous!

Dec 31, 2023 | 08:50 PM

69L88

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From: Apple Valley, MN

Quote:

Originally Posted by n2h2o2

AW = 3.08
116 = day of the year (April 25)
E= Eaton plant
12= should be the shift so maybe this was built on both 1st and 2nd shift?

It is my understanding that all of the differentials were assembled at the Warren, Michigan plant and the E is indicative of the positraction unit which were manufactured by Eaton.

Dec 31, 2023 | 09:09 PM

n2h2o2

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From: Smyrna, TN

Quote:

Originally Posted by 69L88

It is my understanding that all of the differentials were assembled at the Warren, Michigan plant and the E is indicative of the positraction unit which were manufactured by Eaton.

Yes, I believe you are correct...
I think they dropped the "W" for Warren somewhere in 69 or 70...
E is for Eaton Posi unit...but they were still assembled at Warren.
I don't think there was another build plant. (I could be wrong?)
But I never understood why they dropped the W and kept the E since they were all Eaton Posi's after 70...?

Dec 31, 2023 | 10:55 PM

69L88

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From: Apple Valley, MN

This is a case I currently have from a 73 I bought a while back specifically for the 3rd gen posi. The extra W is for the Warren plant.

I have seen other differentials without the W but have not seen one with a “12” as the OP states.

I have no proof one way or the other but I presume the Eaton posi units were “loaded” by Eaton and the subassembly sent to Warren for installation into the differential.

Dec 31, 2023 | 11:21 PM

n2h2o2

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From: Smyrna, TN

You are right...I have a pumpkin from a 74 that has the W and the E...
I am sure I read that they dropped the W at some point...
Now you have me curious to find out why / when there is some without the W...
Yeah...The 12 was new to me as well...

Dec 31, 2023 | 11:31 PM

kansas123

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Melting Slicks

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From: Wichita Kansas

And I am pretty sure mine is AWW also, I had suspected I as missing a digit or two. I can double check that tomorrow if we go above freezing.

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Jan 1, 2024 | 03:05 PM

DWAVette

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From: Baton Rouge, Louisiana, metro area

My 75 has the following:

O A W 282 F 1

for comparison purposes.

I have a L48, 4-speed. I am not sure of the meaning of the markings, but listed them as another example of markings.

Jan 1, 2024 | 03:26 PM

#10

n2h2o2

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From: Smyrna, TN

Quote:

Originally Posted by DWAVette

My 75 has the following:

O A W 282 F 1

for comparison purposes.

I have a L48, 4-speed. I am not sure of the meaning of the markings, but listed them as another example of markings.

OA is listed as 3.08 for 1976 and 1977.
Perhaps you have a very late production 75, or the diff was changed at some point.
check your casting dates, especially on the main case.

As previously mentioned, the W is Warren , the 282 is the day of the year( check casting date)
the F is probably a light stamped E for Eaton, and the 1 is first shift.