65 Rear End Bulid Date Question

[Dennis H.]

I have a 65 that was built Jan 27 1965 with a rear end Assy date/code of AO 12 29 65. For several months I got turned around thinking this was the orginal rear end (I got tunnel vision on the 65 date I guess). Anyway, I found a AO 12 29 64 housing to swap out but want some input on dates.

I know NCRS uses the 6 month rule but what was GM really doing in late 64 to early 65? I have the Noland Adams book but there is not much info on dates vs. Vin numbers for rear ends. From some used stuff I have looked at in the 63-67 range the cast date to assy date can run as little as 2 weeks to 3 months. I don't want to spend good money for something that the dates look too far off but I will be rebuilding this rear end while the body is off so now is the time to find the correct rear end. Thanks

[Harry Sadlock]

Re: 65 Rear End Bulid Date Question

If you have Nolands book, look at page 310, else, what is your sequence number.

An example from the book is 65 sequence number 4738 had rear dated AP 11 64.

I believe the dates vary by rear ratio, meaning AO vs. AR vs. AM, etc

Harry

[Harry Sadlock]

Re: 65 Rear End Bulid Date Question

If you have Nolands book, look at page 310, else, what is your sequence number.

An example from the book is 65 sequence number 4738 had rear dated AP 11 64.

I believe the dates vary by rear ratio, meaning AO vs. AR vs. AM, etc

Harry

[John H.]

Re: 65 Rear End Bulid Date Question

As a side note, transmission and differential "numbers" aren't judged in Flight judging.

[John H.]

Re: 65 Rear End Bulid Date Question

As a side note, transmission and differential "numbers" aren't judged in Flight judging.

[Wayne M.]

Also check casting dates, casting #'s

before discarding one carrier for another. Who knows, maybe the guy assembling the diffs on the 29th Dec was getting a head start on the new year. Have you had a look inside to check the part #'s and dates on the ring and pinion gears ?

Early '65's (at latest to Jan '65, probably earlier in late '64) used carrier 3818753, then changed to 3876476. I've seen casting dates (edge of case below driver side output yoke) that are 2 and 3 months before the assembly stamp date.

P-o-P example: '65 convertible # 4835 with motor F1212HT has rear AL_12_09_64.
(unfortunately I didn't note casting # and date back 38 years ago).

[Wayne M.]

Also check casting dates, casting #'s

before discarding one carrier for another. Who knows, maybe the guy assembling the diffs on the 29th Dec was getting a head start on the new year. Have you had a look inside to check the part #'s and dates on the ring and pinion gears ?

Early '65's (at latest to Jan '65, probably earlier in late '64) used carrier 3818753, then changed to 3876476. I've seen casting dates (edge of case below driver side output yoke) that are 2 and 3 months before the assembly stamp date.

P-o-P example: '65 convertible # 4835 with motor F1212HT has rear AL_12_09_64.
(unfortunately I didn't note casting # and date back 38 years ago).

[Dennis H.]

Re: Also check casting dates, casting #'s

I don't have the casting date date with me but it is strange to 1 year off. I will have a re-look at the casting date before I pull the trigger on a housing.

[Dennis H.]

Re: Also check casting dates, casting #'s

I don't have the casting date date with me but it is strange to 1 year off. I will have a re-look at the casting date before I pull the trigger on a housing.