Where's the rear axle code stamped on a '59?

[Ian G.]

Re: Where's the rear axle code stamped on a '59?

My early 59 (Dec 58) had the steel SEMS washers on the nuts...

[Tom P.]

Re: Where's the rear axle code stamped on a '59?

Here are the two styles of nuts/washers used on rearends up to 62 (55-64 on pass car rears).
The left nut/copper washer were used up through 57 and the right nut had a steel washer swedged to the inside diameter of the nut on 58-later rears.


My personal preference is the plain nut and copper washer. When the nut is torqued, it crushes the copper around the threads of the stud making a better seal against oil seepage.

[Joe L.]

Re: Where's the rear axle code stamped on a '59?

Here are the two styles of nuts/washers used on rearends up to 62 (55-64 on pass car rears).
The left nut/copper washer were used up through 57 and the right nut had a steel washer swedged to the inside diameter of the nut on 58-later rears.


My personal preference is the plain nut and copper washer. When the nut is torqued, it crushes the copper around the threads of the stud making a better seal against oil seepage.

Tom------


The washer pictured is a brake hose washer applicable to Corvettes and other GM cars. It could not have been the washer originally used since this part number only dates back to about 1978. However, it's probably very similar to the original washer and a very suitable replacement. The GM #14000172 was discontinued in April, 1992. The current supercessive part number is GM #21012386.

[Tom P.]

Re: Where's the rear axle code stamped on a '59?

Thanks Joe, that's good to know.

[Tom P.]

Re: Where's the rear axle code stamped on a '59?

Tom------


The washer pictured is a brake hose washer applicable to Corvettes and other GM cars. It could not have been the washer originally used since this part number only dates back to about 1978. However, it's probably very similar to the original washer and a very suitable replacement. The GM #14000172 was discontinued in April, 1992. The current supercessive part number is GM #21012386.

Joe,
I ordered 10 pkgs (they come 10/pkg) of the 21012386. As you mentioned, they are the washers which originally superceded the original 14000172. So, I went and looked through my inventory of copper washers, and it appears that an even earlier number was 10139097, and then prior to that was 1456254. Now, with that said, MAYBE the last two part numbers are for brake hose connections, but they work just fine for installing them under the nuts for the rear end center section. I have no clue how closely the copper washers may be judged, but personally, I like the 14000172 better than the 21012386 which superceded it. I feel the lager 14000172 will do a better job of sealing the studs/nuts against weepage of the rearend oil.

Also, I THINK that ONLY 56-57 Vettes (and 55-57 pass cars) used copper washers/nuts, whereas 58-62 Vettes (58-64 pass cars) used nuts with the integral steel washers, as shown above.
What are your thoughts?

[Joe L.]

Re: Where's the rear axle code stamped on a '59?

Joe,
I ordered 10 pkgs (they come 10/pkg) of the 21012386. As you mentioned, they are the washers which originally superceded the original 14000172. So, I went and looked through my inventory of copper washers, and it appears that an even earlier number was 10139097, and then prior to that was 1456254. Now, with that said, MAYBE the last two part numbers are for brake hose connections, but they work just fine for installing them under the nuts for the rear end center section. I have no clue how closely the copper washers may be judged, but personally, I like the 14000172 better than the 21012386 which superceded it. I feel the lager 14000172 will do a better job of sealing the studs/nuts against weepage of the rearend oil.

Also, I THINK that ONLY 56-57 Vettes (and 55-57 pass cars) used copper washers/nuts, whereas 58-62 Vettes (58-64 pass cars) used nuts with the integral steel washers, as shown above.
What are your thoughts?

Tom------

The GM #10139097 was the first part number supercessive to the 14000172. That supercession occurred in April, 1992. As far as I can tell, the 21012386 replaced the 10139097.

The GM #1456254 was discontinued without supercession in 1983. I can't find that it was ever in the "line of succession" with the aforementioned part numbers.

It looks like with the 21012386 GM was trying to "slim down" the washer, probably influenced by the price of copper. However, it should still seal well. I can't see GM "cutting corners" on a brake system part that would compromise system performance or durability. Since this gasket/washer is designed to work in a system with 1000+ PS!, it should seal quite well in the differential bolt application.

There is another brake system washer of GM #231343. According to GM, this washer is supposed to be 7/16" ID X 11/16" OD and 0.032" thick. It's still available from GM.

Otherwise, you may be able to obtain washers like the 14000172 from sources like Dorman Products.

[Joe L.]

Re: Where's the rear axle code stamped on a '59?

Tom------


From what I can tell, the GM #231343 is very close to the 14000172 in configuration. It's also very close in configuration to the GM #1456254, which was the washer originally used for the differential bolt application. It might be a little thicker, though.

However, I still think the GM #21012386 should function as well as any for the differential bolt application.

[Tom P.]

Re: Where's the rear axle code stamped on a '59?

OK, thanks.

[Joe L.]

Re: Where's the rear axle code stamped on a '59?

OK, thanks.

Tom------


By the way, this GM #231343 is an absolutely ancient part number. It dates back to at least the 1930's and has been continuously available in SERVICE since that time to this very day.

[Robert I.]

Re: Where's the rear axle code stamped on a '59?

Can someone translate the code on the passenger side of the differential on my 62? It's CM612differential number.jpg

Thanks

[Tom P.]

Re: Where's the rear axle code stamped on a '59?

Bob,
What is the CASTING date on the driver side-----------------specifically, the last number?