47-59 Help with ID on rear end

[johnsgreenstore]

I have a 1955 series 2 GMC truck, at some point a different rear end was installed. I am struggling to get complete brake componets. 12 bolt with stamped on left tube GK 100462 Cast with GM 68 and cast with 8894860 NF. Can someone tell me what rear end is under my truck, Please. John

[mongocanfly]

got any pics of it?
are you sure the 1st number isnt a "3" ??..8894860 ..instead maybe 3894860.
this 3894860 comes back to a camaro/nova

[Getter-Done]

Mongo you are probably right

johnsgreenstore does it look like this one in the link below?

Link: https://www.ebay.com/itm/28521897858...Bk9SR5jO3ZDZYg

[johnsgreenstore]

[ATTACH]



[/ATTACH] Thank you, hope they went thru

[johnsgreenstore]

Made a mistake on stamped axel, GK 1004G2

[Getter-Done]

Originally Posted by johnsgreenstore

Made a mistake on stamped axel, GK 1004G2

Maybe QK ?

Check out this link.

Link: http://www.camaros.org/drivetrain.shtml#AxleCodes

[johnsgreenstore]

I went to shop and buffed with steel brush, it is in fact 3894860 NF housing and stamped in the left tube is GK1004G2. I looked with heavy cheaters and it is a G, so I am stumped, because specs on a Camaro rear brake pads and drums are to small for my application, having bought the wrong ones twice now. And thanks for your trying to help. Regards John

[dsraven]

something here help you?
https://www.differentials.com/techni...dentification/
do you not have the old stuff to compare?

[leegreen]

Are the axles 5x5 or 5x4.75?

full size car and half ton trucks from the 70's should have the same backing plate, but the wheel cylinders, drums and shoes are different . Unless maybe you have a police spec axle or some kind of heavy duty car like a big wagon.
Camaro brakes were smaller than full size

So if you have 5x5 I'd try looking at brakes from a mid 70s C10, 5x4.75 try a full size car. If you have the old drums & shoes the diameter and width will be significant and something you should be able to check before you order new stuff

That axle looks like it might have had stuff torched off, like control arm mounts so maybe it is from a sedan. Do spring perches look like they were added?

[dsraven]

backing plates can be swapped to match the brake set up you want, if that helps at all. yes, the cover will need to be removed to pull the "C" clips and release the axles but then wouldn't you wanna see what you have inside there anyway? take the carrier out and flush the housing and axle tubes, check bearings, check axle bearing wear surfaces, replace axle seals, etc etc?
if you just wanna see the size of shoes needed you can lay a flat edge bar across the axle flange and measure back to the backing plate, that will give a rough idea. knowing the wheel bolt pattern will vastly narrow down the possibilities as well.

[mr48chev]

The signs of all the brackets being cut off makes me pretty sure that it is a 65 or later B Body (Impala size) 12 bolt.

There isn't a lot of info on B body 12 bolts but if you scroll down this page to the 12 bolt section there is info that you can use https://www.chevydiy.com/history-and...differentials/ Scroll to the bottom of the page past the 10 bolt section.

I had a 66 Caprice/Impala 12 bolt Posi under my 48 when it was subframed and I wish I had kept that rear axle.

The GK stamping on the tube isn't jiving so far though.

[mr48chev]

Well my hunting paid off It's out of a 67/69 full size Chevy and has 2.73 gears. Not much for drag racing but with a turbo 400 or 350 in front of it you can run a lot of us into the ground on the big long roads.

I had to get over on a 409 forum to find it. Someone did a lot of work on that page. http://www.348-409.com/differential.html