Differential date code

[Michael J.]

I have a 1966 L79 coupe and wanted to check the date code on the differential, but where exactly is it located? I can't see any numbers on a brief instectio, except some vertically cast numbers on the passenger side rear of it. Is it visible without taking parts off? Thanks.

[Gary R.]

Re: Differential date code

casting date is on the lower LH side under the yoke, in the corner. Sometimes they're upside down. The assembly code is stamped in the bottom of the housing by the rear cover gasket.

[Michael J.]

Re: Differential date code

Got it, thanks.

[Wayne M.]

Re: Differential date code

Michael -- here's the OTHER side of the diff; see where the casting clock is ? (circle of dots with pointer). At exactly the same location on the driver's side is where the date will be found. Note: on this side, is the casting number of the carrier (3818753-N on this one, from early '65 car).

If the diff is in the car, the strut rod bracket (that bolts to the bottom of the carrier) may hide the casting date from a direct view.

[Michael J.]

Re: Differential date code

Thanks, and yes after struggling around, it is obvious that this can't be seen unless the struts and bracing frames are removed, I'm afraid it will have to wait until some serious work is done. Guess this is why the NCRS judging never looks at this?

[Wayne M.]

Re: Differential date code

Thanks, and yes after struggling around, it is obvious that this can't be seen unless the struts and bracing frames are removed, I'm afraid it will have to wait until some serious work is done. Guess this is why the NCRS judging never looks at this?

Michael -- while difficult, it is not impossible to read the casting date: viz. this one D_10_5 (trust me ) on a '65 on jackstands (circled). After a mouthfull of rust and dust, and a good wire brush and trouble light, were able to determine this one.

[Michael J.]

Re: Differential date code

OK, that gives me a much better idea. I'll try again on the lift, mine is pristine compared to that one, it was all restored not long ago and hasn't been driven much. I have the numbers on the list that was checked before I bought it, I was just double checking everything as I get time. Thanks again.