Eaton Posi assembly date

[bcmiller]

All Eaton 12 bolt posi carriers received a stamped assembly date code. The code was in the format of letter / number / letter. It seems be be fairly well known that J was used for 1969. Do we know the letters used for 1965, 1966, 1967 and 1968?

Thanks in advance.

[Lee Stewart]

https://www.onedirt.com/tech/drivetr...rearend-guide/

This help?

[big gear head]

He is asking about the letters stamped on the outer edge of the ring gear flange on the Eaton Posi case. I've got cases that are stamped F, G, H and J. I think everyone knows that J is '69, but what are the others? The 12 bolt was produced from '65 to '72. Did these codes continue the same on the Eaton Posi case to '72?

[m22mike]

Originally Posted by bcmiller

All Eaton 12 bolt posi carriers received a stamped assembly date code. The code was in the format of letter / number / letter. It seems be be fairly well known that J was used for 1969. Do we know the letters used for 1965, 1966, 1967 and 1968?

Thanks in advance.

I think they used letter A to k. For the year (did not use I ) J being 1969 you should be able to count back from there.

[BCreekDave]

So you could have a JJ (October 1969)? By the chart letters are for months up to 1971

[bcmiller]

It would make sense that they didn’t use the letter I for year - but I swear I had one a few years ago with the year letter stamp being I. I could be wrong or suppose it could be later. Although they stopped being used in production in 1972, they were made much later.

Here is a later one. Year code JC - maybe 1993?

[bcmiller]

Originally Posted by BCreekDave

So you could have a JJ (October 1969)? By the chart letters are for months up to 1971

The format is letter number letter. Here is one stamped C 22 H from a 10 bolt 3 series posi.

[big gear head]

So assuming that the E would be for the first year of production in '65, then F would be '66, G would be '67, H would be '68, J would be '69, K would be '70, L would be '71 and M would be '72? Can anyone verify this with something from '70 to '72?

[MarcDant]

Here is jan. 22 assembled rear gear.

[bcmiller]

Thanks for posting that. The posi assembly date stamp is late 69, fits fine for a Jan 1970 axle assembly.

Would anyone have data from other years they would want to post from original axles?