C2 64 Differential Markings & Alignment

[Alan Drake]

Question on Mar 64 FI car with 4:11, all numbers appear to be as expected.

The casting number on the rear upper section of case is the 3818753 – N, What is the N for?

The drive shaft at the rear end has green paint approx 2 1/2 long by 1/2 wide along the length of the shaft.

I assume it’s a balance marking, does it align with the counter weight welded on the rear end's Flange Deflector, pn 3841822? Or is it 180 degrees from weight?
On the same Flange Deflector on the area covered by u joint is the number 823 - ?

The upper portion of the carrier and the Flange Deflector show remains of black paint, were any of these painted???

[Jack H.]

N= Nodular iron the source foundry... *NM*

[Wayne M.]

Another '64 Diff "CD_1_3_64"

Alan -- Here's another 3818753-N. Notice the threaded forward bracket hole on each side of the nose. Not sure about the green paint on the driveshaft, but the yellow and blue paint inspection marks (especially the blue) are more prominent on the yoke side that has the balance tab on the deflector. This also has the "823" yoke (14 pinion gear splines) rather than the "986" (20+ splines) yoke that started with the 65 MY. You can barely discern the "823" cast in the pic.

My early '65 car, 014xx, also has same "753" carrier but with the "986" yoke (the yellow and blue paint marks are much more extensive). Like yours, it is a 4.11 ratio [AP_9_17_64] and has a 3 inch diameter "splotch" of black paint on the top of the rear cover, which is incidentally a "303" similar to the one on the diff pictured above, except it has the '65-up tapered coarse thread filler plug (talk about running changes).

Does yours have a stamped "C" and "E" close together, on the top of the casing half way between the cover flange and the yoke ?

[Alan Drake]

Re: Another '64 Diff "CD_1_3_64"

Thanks Wayne,
My unit is marked CE 3 10 64, is a 303 with the GM 6 and a date code of B14, however I've been told that these units did not have a date code.

The two foward holes are threaded on both sides while the rear hole has the tru bolt.
The yellow also has a little blue which is 180 degrees from the balance tab.

I just cleaned it with Simple Green and will check again for the C E on the top, but have not seen it so far.

If you desire any pictures send me your email, haven't been able to post pictures yet, problem with my IP not the board.

[Alan Drake]

Re: Another '64 Diff CE

Wayne,

Unable to find your CE marking on top of case.

As for the black paint on my diff. It appears that some black paint was applied to the Diff at least at the back. Why do I say this?

Well used a small wire brush at the top of the flange assy (york area) to expose some of the yellow paint. Yes yellow was exposed, however bright metal was also exposed where the yellow paint wasn't. If the flange was exposed for a short time it would rust, but under black paint it was bright!

[Wayne M.]

I'll email you a couple of jpegs of these marks

if you send me your email address. I don't think I can attach photo files to an email sent via the NCRS link below the title line of each board post.