Eaton Posi assembly date
 

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.

https://i.postimg.cc/Kjk7yrnH/screenshot-7623.png

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

This help?

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?

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.

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

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?

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

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?

70 date
 

Here is jan. 22 assembled rear gear.

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?