Eaton Posi Date

[HawkX66]

What's assembly date of posi

Original poster was asking about the posi unit stampings...  NOT the gear stampings..

Ah. If that's the case, I couldn't tell you. I don't think it was stamped, otherwise I would have taken a pic of it. I could have missed it though.
 Now that I'm reading it a little closer, my guess is he was asking me for the date the whole posi rear end was assembled. If so... 8/20/69

[hihorse]

Dave,
Stamping on right tube is assembly of Diff. Was looking for assembly date of posi carrier which is located on flange that ring gear is bolted to.

[bcmiller]

I am not sure they all were stamped with a date.

[bertfam]

Here's a 2 series and a 3 series posi carrier I have. E 10 8, and J 7 4 (or J 7 A, hard to tell).

Ed

[bcmiller]

The only one I have easy access to here is a 3 series stamped F 2 J

I had a 4 series a while back that was just stamped 8

Honestly unless you have a COPO car, who cares about the date? It’s not going to be judged or checked unless it needs to be verified as a 4 series with correct COPO internals, which are different than regular posi internals. Now having correctly dated gears (and housing) IS important in my mind. Just my 2 cents. 

It’s ok to be mindful of the numbers, just don’t fall over the edge to OCD. 

[bcmiller]

And I just chatted with a person that deals with rear end internals every day for his business.

With the new Eaton style posi units being sold today, the internals and cases are a lot stronger than the originals.  Prices on the new ones are typically the same or less than an old rebuilt unit.  Just FYI.

[bertfam]

That E 10 8 posi I posted above could be an E 10 B. Hard to tell.

Ed

[hihorse]

The only one I have easy access to here is a 3 series stamped F 2 J

I had a 4 series a while back that was just stamped 8

Honestly unless you have a COPO car, who cares about the date? It’s not going to be judged or checked unless it needs to be verified as a 4 series with correct COPO internals, which are different than regular posi internals. Now having correctly dated gears (and housing) IS important in my mind. Just my 2 cents. 

It’s ok to be mindful of the numbers, just don’t fall over the edge to OCD. 

All assembly dates including one Eaton stamped on the posi carriers is important to me whether car is being judged or not.

[bcmiller]

And that’s your choice. Whatever...

I mean either it’s either original to the car or not.

Mine isn’t - because it was originally a 3.73 open rear end.

[bcmiller]

I MAY have an answer on the stamped code for the late 60s.  I have no confirmation on this, just speculation.

The stamped assembly date code can either be on the edge of the ring gear flange, or on the end (see pic below of one I have from a Chevelle).  The stamped format of the digits is month, day, year.  Month and year are letters with just the last digit of the year.  I need to figure out which letter was not used for sure, but it is most likely the I, which is not used for other stamped dates (such as on distributors).

The one attached is H24H - which COULD be August 24, 1968.

For the year 1969, the year stamp would be a J (the letter). I am fairly certain that J in the year position corresponds to a 9. 

In the pic I posted, it has a normal casting date F 14 7 which is June 14, 1967.  The casting date on some units may only have the Julian date (day of the year 1 to 365).  I do not know why the casting date and assembly date would be so far apart, it seems unusual.

(Edited)

[bcmiller]

Typically things like distributors that are date stamped use the following (I is not used for month).
A for January
B for February
C for March
D for April
E for May
F for June
G for July
H for August
J for September
K for October
L for November
M for December

For the year
A - 1
B - 2
C - 3
D - 4
E - 5
F - 6
G - 7
H - 8
J - 9
K - 0

[bcmiller]

If anyone has an original please post the date stamp on the carrier, axle housing assembly date and date of the vehicle assembly.  Thanks.

I may start a thread in Research topics.

[janobyte]

F227 is the code on my carrier. June 22nd, 67? Still have original ring and pinion packed away. Can post those dates if anybody is interested.

Somebody just pm'd a few weeks ago asking me about the casting date on the carrier.

[janobyte]

And I just chatted with a person that deals with rear end internals every day for his business.

With the new Eaton style posi units being sold today, the internals and cases are a lot stronger than the originals.  Prices on the new ones are typically the same or less than an old rebuilt unit.  Just FYI.

Yup. Really the way to fly is a bolt in 9" with a nodular iron third member.

[janobyte]

BV 0424 G1 axle tube. Car is a 04D build.