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Old 06-03-2014, 11:20 PM   #1
1slo_camaro
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12 bolt

Just picked myself up a good 12 bolt for 200 bucks....


I was told it came out of a 79 cheyenne 2wd sbc truck. its a 12 bolt with 5 lug axles.

I havent popped the cover yet to figure out the gears, but I have never seen a 5 lug 12 bolt unless it was out of a car. I dont see a tag or numbers anywhere either.

Ill try and get pics up tomorrow.

Is this a *rare* axle, very common axle? what can i expect to pay for a locker and gears?
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Old 06-03-2014, 11:35 PM   #2
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Re: 12 bolt

They aren't everywhere but they're not rare either. It could have about anything for gears, the limited slip will more than likely be a shelled G80 Gov Lock unless someone has already swapped it out for something else. Usually the tag is on one of the cover bolts and gets tossed in the trash the first time someone changes the oil. I don't know why but that seems to be the fate of those tags. There could also be some numbers on the axle tube but those are usually hard to find and read because they are rusty and crusty. You'll know right away what the ratio is when you take the cover off, the tooth count should be on both gears. You'll also see what it has for a carrier, if its a G80 or other.
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Old 06-04-2014, 12:37 AM   #3
Twisted78SS
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Re: 12 bolt

I guess I was a bit surprised when you asked if it was rare, in reality, from late 71 or early 72 on, half ton 2wd trucks made the switch from 6 to 5 lug axles in the 12 bolts (among other axle styles, Dana, Eaton etc...) so they are everywhere.. They are a bit different than a car 12 bolt, I believe the car actually had a bit larger pinion shaft diameter. The ring and pinion are not interchangeable between cars and trucks either. The vast majority seem to be open carriers, and gears came in quite a wide range. For a posi, the Eaton limited slips were the one's I've seen the most.
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Old 06-04-2014, 08:59 AM   #4
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Re: 12 bolt

I swapped in 12 bolt 3.08 axle into my '83 out of a '77. Fit like a glove. I just had to buy an adapting ujoint. The ujoints are smaller on a 12 bolt than a 10 bolt.
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Old 06-04-2014, 01:30 PM   #5
1slo_camaro
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Re: 12 bolt

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Originally Posted by gchemist View Post
I swapped in 12 bolt 3.08 axle into my '83 out of a '77. Fit like a glove. I just had to buy an adapting ujoint. The ujoints are smaller on a 12 bolt than a 10 bolt.
yea that would have been bad to find out because I almost tore my 10 bolt out this upcoming weekend and figured hell... its just a quick swap.. and this being my daily driver right now. That would have turned out bad lol


Thanks for the info guys im stoked to have it I can only assume itll hold better to power than my 10 bolt will so thats why I grabbed it
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Old 06-06-2014, 03:48 PM   #6
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Re: 12 bolt

http://www.napaonline.com/Catalog/Ca...348_0439017295


Is this what you used for the U-Joint?
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Old 06-06-2014, 05:00 PM   #7
motornut
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Re: 12 bolt

i think you may have a number just next to the rear housing case, my 12 does....G80 if its the locker
not real popular around here,but mine are ok so far
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Old 06-06-2014, 09:03 PM   #8
1slo_camaro
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Re: 12 bolt

I have to get this thing in the garage that my roomates are cluttering up so I can get this on jack stands and clean the housing up and get some paint on her and than I have to build the breaks....

I am sure the brakes are different on this as opposed to my 10 bolt correct? If so how can i make sure I am getting brakes for a 12 bolt and not a 10 bolt if going through rock auto or autozone or whatever??
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Old 06-07-2014, 09:36 AM   #9
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Re: 12 bolt

Quote:
Originally Posted by 1slo_camaro View Post
I have to get this thing in the garage that my roomates are cluttering up so I can get this on jack stands and clean the housing up and get some paint on her and than I have to build the breaks....

I am sure the brakes are different on this as opposed to my 10 bolt correct? If so how can i make sure I am getting brakes for a 12 bolt and not a 10 bolt if going through rock auto or autozone or whatever??
when it gets weird (parts swapping),I bring stuff in (store), with me to order
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Old 06-07-2014, 06:16 PM   #10
1slo_camaro
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Re: 12 bolt

I cant. its bare I have nothing on it. and carrying in a 12 bolt rear will get a little heavy
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Old 06-07-2014, 06:31 PM   #11
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Re: 12 bolt

I'm in the same situation, going from a 10 bolt to a 12 bolt on a 61'. I'm picking my new rear end up in a couple of days, it's off of a 67'. The one I found will most likely need new brakes, but it does have the old one's still attached. I can either email you some pictures or once I get them removed, send them to you if you like.
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Old 06-07-2014, 07:25 PM   #12
1slo_camaro
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Re: 12 bolt

if you can just post it all up on here and all. it might be different being from a different Gen truck
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1998 Jeep ZJ 4.5 lift 32s full bolt ons awaiting axles

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Old 06-07-2014, 09:14 PM   #13
bigblock73
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Re: 12 bolt

Not rare at all, standard rear in the 73-80 or 81 I believe 1/2 to trucks, blazers and suburbans. It is NOT the same as a passenger car 12 bolt however.
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Old 06-07-2014, 11:29 PM   #14
1slo_camaro
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Re: 12 bolt

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Originally Posted by bigblock73 View Post
Not rare at all, standard rear in the 73-80 or 81 I believe 1/2 to trucks, blazers and suburbans. It is NOT the same as a passenger car 12 bolt however.
the 6 square bodies ive owned have always had 10 bolts
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