2nd gen f-body 3.42 posi 12 bolt

[alamantia]

Found it in a garage, A-body 3.73 posi complete drum to drum but needs a yoke. Pick it up for $300

http://i181.photobucket.com/albums/x97/alamantia/12complete.jpg

http://i181.photobucket.com/albums/x97/alamantia/12posi.jpg

[Tru2Chevy]

Hmm....I don't suppose you mean one of the 78-82 "A" body cars, do you?

If so, I'm 99% sure my brother will take it for his '79 Malibu.

- Justin

[00 LS1]

Thats a OLDS 12bolt with a 8.5" center section from a 68-72 A-body 442 or Cutlass 8-)

[alamantia]

not 100% sure what its for, seems the pads have already been relocated, you can grind them off and weld them where ever

[00 LS1]

Those are leaf spring pads it was made into a 70-81 F-body rear probably around 54" from backing plate to backing plate ....The coil spring and lower control arm mounts are long gone 8-)

[alamantia]

good info, i guess in that case it makes this an f-body rear

[76bumblbrally]

if you can measure the distance between the spring mounts, and the end of the axle plates and you can garuntee that this rear is in good working condition i will take it, PM me the info once you have it

[alamantia]

looks like about 45" between center of pad to center of pad and about 54" between backing plate and backing plate

[76bumblbrally]

ill check my measurements tommorow and let you know

[alamantia]

Those are leaf spring pads it was made into a 70-81 F-body rear probably around 54" from backing plate to backing plate ....The coil spring and lower control arm mounts are long gone 8-)

wouldnt this fit a 1st gen too?

[00 LS1]

wouldnt this fit a 1st gen too?

Might be too wide for a 67-69 it depends on the placement of the spring pads 8-)

[BonzoHansen]

I'll measure the 2nd gen posi I have in the back yard when I get a few minutes. A 2nd gen rear will not fit a 1st gen.

[BonzoHansen]

Added info....

That is correct. The '67 to '69 Camaro and '68 to '75 Nova rear ends are the same width (60 inches) and the spring perches are in the same location (42 1/2 inches center to center) and will interchange. The '70 to '81 Camaro rear ends are 61 inches wide and the spring perches are 45 1/4 inches center to center.

[transamkid]

so what car is this for?

[alamantia]

yeah, what car is it for?

looks like this

http://www.racingjunk.com/post/1204178/12-Bolt-Rear-End-Out-Of-1970-Camaro-Z-28.html

[WildBillyT]

Measure perch to perch and that will tell you.

[alamantia]

Here we go, i found the answer....

it IS a 2nd gen 12 bolt, they only made a 12 bolt in the 1970 second gen which came with the 396, every 2nd gen year after that got a 10 bolt.

http://www.nastyz28.com/camaro/zsusp.html

Camaro Rear Axle Information
The 1970 rear end differs from the 1971-1981 rear end. In 1970 the rear end was built in both 10 and 12 bolt versions. In 1971, GM instituted a standardized "corporate" rear axle. This rear end was available in a 10 bolt version only. The 1970 12 bolt version will bolt into any second generation Camaro and quite often is done so in high power applications.
Three piece housing includes integral cast iron differential carrier and housing with pressed in and welded steel tubes.

Semi-floating forged and heat-treated axle shafts. Wheel drive flange is forged integral with the axle. Axles are the same length for both sides
.
Differential carrier contains hypoid overhung pinion and ring gear. Drive pinion supported by two taper roller bearings.

Rear Suspension - Salisbury rear axle with multiple leaf springs.

Staggered shocks, right side shock is located in front of axle tube and the left shock is located behind the axle tube. This controls wheel hop.

Leaf Springs - All leaf springs were 5-leaf design, 56" long, 2.5" wide.
See yearly info for specific specifications.

Physical Dimensions
1970 10 bolt 1970 12 bolt Corporate
Bolt Diameter 3/8" 3/8" 7/16LH
Ring Gear Dia 8.20" 8.875" 8.50"
Pinion Dia. 1.438" 1.625" 1.625"
Axle Splines 28 30 28

The following dimensions are consistant across all 3 style rear ends.
Axle tube flange to axle tube flange: 55.25"
Between centerlines of spring seats: 45 3/8"
Axle shaft length: 30 5/32"

[BigAls87Z28]

Well it WAS for an A/B body car, but was turned into something for a 2nd gen Fbody. The control arm bosses that are attached to the housing of the diff are for the 4 link set up that is found on A/B bodies.

[alamantia]

well its on EBay now...

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&_trkparms=tab%3DSelling&viewitem=&item=160263947203&_trksid=p3907.m32

...and i found out that despite what the ol timer who gave it to me said its actually a 3.42 ratio and not 3.73's

[JerzyIroc]

would this go right into a 74 nova?

[alamantia]

http://novaresource.org/axle.htm

[alamantia]

Posi & Gears sold on Ebay on 7-25-08, I have to yank them and ship them on monday. I am still left with a solid 12 bolt housing, bolt in (non C-clip) axles, backing plates, brake hardware & diferential cover. If anyone wants that stuff for their second gen come pick it all up for $50 and order a nice posi and gears and have yourself a good solid rear axle.