[Curnane]

Need some help here I'm gettin confused I just pulld a rear end out of a 64 gto the docs say
its 323 k the stamp on the axle says 323 L I know its the origanal rear end and I see no reason why they would have been changed . did this have some thing to do with the brakes is there something on the docs im missing Theres no L in the axel codes

[JAKE 64]

If you look real close, you should also be able to see the letter P ahead of the number. I may be able to see a little of it in the shadow. The code signifies that you are equipped with the optional Safe-T-Track differential. It appears from the picture that the differential has been media blasted. If so, prior to blasting, you may have noticed some extensive paint colorings on the pumpkin. The colors green and brown, if noted, would also indicate the 3:23 limited slip differential. (Green for the 3:23, and brown for the limited slip). Prior to blasting, and depending on the milage, could you offer a comment on the extent of paint on the axle tubes and pumpkin? Was there much evidence of black paint on the forward side of the unit?

[Curnane]

Thanks Jake I did not have much choice but to media blast there was a lot of surface rust there was a trace of green paint on the pumpkin. not worth saving no trace of black or brown left . the car had option G80 Dif Positract the date on the rear preceeds the build date for the car by 3 weeks I know its origanal what I would like to know is what does the L stand for

[Curnane]

forgot to mention there were 2 of these both in the same place

[Curnane]

Originally Posted by JAKE 64

If you look real close, you should also be able to see the letter P ahead of the number. I may be able to see a little of it in the shadow. The code signifies that you are equipped with the optional Safe-T-Track differential. It appears from the picture that the differential has been media blasted. If so, prior to blasting, you may have noticed some extensive paint colorings on the pumpkin. The colors green and brown, if noted, would also indicate the 3:23 limited slip differential. (Green for the 3:23, and brown for the limited slip). Prior to blasting, and depending on the milage, could you offer a comment on the extent of paint on the axle tubes and pumpkin? Was there much evidence of black paint on the forward side of the unit?

Jake what would the code have been for Safe-T Track 3 23 (Standard Axel)

[gtoric]

Curnane, did your car come with the metallic brakes option? If so, that's what the L stands for, 3.23 ratio w/metallic brakes. 3.23 w/standard brake linings is K.

[Curnane]

ill take a look and get back to you thanks

[JAKE 64]

It has always been my belief that the "P" preceding the ratio "number" stood for Pontiac. In 1964, Pontiac chose to actually list the gear ratio used on the car, and stamped this on the right axle tube. The "L" most likely stood for "Locking" as in limited slip (posi). Only a maximum of three digit groups may appear on your axle tube, the "P" for Pontiac, the three numbers for the gear ratio, and the "L" if the car is equipped with the "L"ocking (posi) feature. If it is an open rear, the "L" will be missing. Some of the other codes pertaining to the axle such as the metalic brake feature could be found on a drum attached sticker, or on the PHS manifest. Color coding was also used on the pumpkin, notating ratio and the provision of locking/nonlocking differential. Any notation referencing metalic brackes will not be stamped on the axle tube. The reference for metalic brakes would need to come from the drum attached sticker (if still present) or the PHS Manifest.

[Curnane]

Originally Posted by JAKE 64

It has always been my belief that the "P" preceding the ratio "number" stood for Pontiac. In 1964, Pontiac chose to actually list the gear ratio used on the car, and stamped this on the right axle tube. The "L" most likely stood for "Locking" as in limited slip (posi). Only a maximum of three digit groups may appear on your axle tube, the "P" for Pontiac, the three numbers for the gear ratio, and the "L" if the car is equipped with the "L"ocking (posi) feature. If it is an open rear, the "L" will be missing. Some of the other codes pertaining to the axle such as the metalic brake feature could be found on a drum attached sticker, or on the PHS manifest. Color coding was also used on the pumpkin, notating ratio and the provision of locking/nonlocking differential. Any notation referencing metalic brackes will not be stamped on the axle tube. The reference for metalic brakes would need to come from the drum attached sticker (if still present) or the PHS Manifest.

Jake good information one more question I see there was 3 codes on the manifest 701 702 and 703 my code is 703 which I understand represents both 701 and 702 so I assume 703 did have the locking posi ?????

[JAKE 64]

For 1964 (not counting the M21/3.90 - which was an option) there were essentially two "standard" gear ratios offered by Pontiac. Depending on how the car was equipped, the 3.55 and 3.23 ratios were "standard". Later in the production year, the 3.55 gave way to the 3.23, and all "standard" gear ratios were 3.23. The sales code number 701 is for the Safe-T-Trac differential. The sales code number 702 is for the "standard axle. The sales code number 703 is for the Safe-T-Trac Standard Axle. So, depending on the date (predominant) your car was manufactured, the standard axle at the time of its manufacture would have been the 3.23. Being code 703, it was also equipped with the Safe-T-Trac feature.
(Note: The corporation often combined the last digit of two or more numbers to create a code for a grouping or specific item. In your case, the 70'3' was formed by combining the 70'1' (Safe-T-Trac) and the 70'2' standard axle by adding the '1' and '2' to form
70'3'. Another example is the performance axle is sales code number 708. When you combine the sales code number for the Safe-T-Trac axle of 701, you form the sales code number of 709, which is the code used for the Safe-T-Trac Performance Axle).

On one of my '64's, the differential had green and yellow paint markings, which should indicate that the car is equipped with a 3.08 locking differential. However, the axle tube is marked P 3.23 L. Evidently, in this example anyway, the paint code was not a good indicator of what was present. You should also not rely on the stainless steel tags that are secured to the pumpkin. The best method, and the one I used to confirm what was actually present in this case, is to turn one of the rear wheels, while counting the revolutions of the propeller shaft and observing the action of the opposite rear wheel. The back end of the car will need to be raised off the ground. This will give you both the ratio and determine if the Safe-T-Trac feature is present. You could also open up the pumpkin, which will take a little longer, and is a little messier.

[Curnane]

Originally Posted by JAKE 64

For 1964 (not counting the M21/3.90 - which was an option) there were essentially two "standard" gear ratios offered by Pontiac. Depending on how the car was equipped, the 3.55 and 3.23 ratios were "standard". Later in the production year, the 3.55 gave way to the 3.23, and all "standard" gear ratios were 3.23. The sales code number 701 is for the Safe-T-Trac differential. The sales code number 702 is for the "standard axle. The sales code number 703 is for the Safe-T-Trac Standard Axle. So, depending on the date (predominant) your car was manufactured, the standard axle at the time of its manufacture would have been the 3.23. Being code 703, it was also equipped with the Safe-T-Trac feature.
(Note: The corporation often combined the last digit of two or more numbers to create a code for a grouping or specific item. In your case, the 70'3' was formed by combining the 70'1' (Safe-T-Trac) and the 70'2' standard axle by adding the '1' and '2' to form
70'3'. Another example is the performance axle is sales code number 708. When you combine the sales code number for the Safe-T-Trac axle of 701, you form the sales code number of 709, which is the code used for the Safe-T-Trac Performance Axle).

On one of my '64's, the differential had green and yellow paint markings, which should indicate that the car is equipped with a 3.08 locking differential. However, the axle tube is marked P 3.23 L. Evidently, in this example anyway, the paint code was not a good indicator of what was present. You should also not rely on the stainless steel tags that are secured to the pumpkin. The best method, and the one I used to confirm what was actually present in this case, is to turn one of the rear wheels, while counting the revolutions of the propeller shaft and observing the action of the opposite rear wheel. The back end of the car will need to be raised off the ground. This will give you both the ratio and determine if the Safe-T-Trac feature is present. You could also open up the pumpkin, which will take a little longer, and is a little messier.

THANKYOU

[dld]

I have followed along the thread. A pertaining question on 64 rear case numbers. could one of you guys enlighten us on what is the casting number on the housing (or part #) that is molded in the center section. Don

[Curnane]

9773369

[dld]

Thanks!