Gentlemen....I can't seem to narrow down the year of this s-10 rear I have. 2.56:1 gear ratio which tells me it may have been with an OD tranny brake drums are 9 1/2 inches (#3853714) 10" backing plate brake cylinder has 15/16 bore AXLE No. 2 E B O 2 8 6 stamped on axle 7.5 10 bolt rear (4 pointed lobes on housing) rear casted no. 555771 ( on bottom ) thanks for any help
Most likely it's from an older truck without overdrive. I've never seen one lower than 3.08 before. Also if you pull an axle to check the spline count it'll narrow it down. Older is 26 newer is 28.
no other casting numbers on the housing? Did you pull the cover and look for the month/year stamped on the ring gear?
Yes on the top of the housing facing the drive line is the number #276. and in addition if you were to travel clockwise around the rear to 3:00 it boasts the letters "CFD". I believe I read that this is a 2 series carrier.....does that help? The PINION bears the numbers...51581.....280......41 x 16.....GMIPN The RING GEAR bears the numbers...41 x 16......KS280
The OD tranny had a 4.10 gear if it is the first gen body. No help I know. In '88 the 2wd rear was 54.25 flange to flange. The 2wd rears were all that width for that gen body as I have been told. Camero and Firebird brakes from that era are a bolt on as well as the third member being a direct swap.
I HAVE ADDITIONAL INFORMATION!! This a 26 count spline. Another # found on axle tube that runs around the tube on the bottom...B38912 Also just out side the rear cover on the gasket face (left) is stamped L12 Pinion # is G M 1 P N ......51581 280
Good info! So I was told wrong about the car when I bought it. Possibly not a S10 rear. I was trying to buy break cylinders for the rear and the closest someone was able to tell was to buy ones for a 73 chevelle. all looked good but the large hole in the backing plate was 1/8 too small to accept the new cylinder...
do NOT call your gm dealer. I'm a gm parts man. our computers are set up to catalog parts by year make and model.
Nope...Astre and Sunbird etc were all coil spring cars and this rearend had leaf pads. The wheel cylinder should be held to the backing plate with a large round clip with 2 tabs if it were an early S10.
as far as gear sets, I have two S-10 rears, both out of 4.3 powered 4X4's, (93 & 94)that are 3.73's, both are gov-locks. Perfect width for early 50's GM cars. cav
that gear, with an overdrive, would be useless in a s10 equipped with 110 horse power. very few 7.5" leaf spring rearend choices exist. 2wd and 4x4 are different widths, and the gear ratios weren't 2.56 on any i know of. mine is a 3.42. just curious, how you arrived at that ratio.
I think the highest ratio was a 2.73 or 2.76. I had a 3.42 in a 350 S10 I built a few years ago. Spring pads are onthe bottom of the axel on S trucks. That does'nt look like an S10. Maybe a late 70s 6cyl Camaro or Nova.
I always consider us to be rather fortunate here in western nowhere Kansas, the parts manager at the Buick/GMC dealership has keep a library of old and outdated manuals and catalogs and has been able to help me find all manner of parts with casting numbers and the like. The Ford dealership a couple towns over is the same way. The parts man there even keeps the microfiche machine up and running. I was completely wrong on the spring pads. Not sure what I was thinking, apparently I wasn't
Don't include any confusion with Camaro or Nova rearends with factory leaf sprng pads. They were either early 8.2s or 8.5s. In both cases they had 28 spline axle shafts and boxes under the rearend housing for the rubber pads that sandwiched and located the leaf springs. Correct dates up thru 1981 for this information. If I was going to guess what that rearend is, I would lean toward an early S10, but have an idea the Monza possibility is a very good possibility. 2.56 gears would also age it toward the Monza possibility because I don't think any of those cars had an overdrive transmission. BCA/National seal catalog also shows 7.5 GM rearend from 76-79. I use this catalog for a good foundation on some stuff.
please keep adding info here-I am one of those that bought a project with much work done by a previous owner. so, have to guess at what I have at times. S10 set ups are so common that there has to be more of us here that do not really know what they have
As I said, its not Vega, Astre, Monza, Skyhawk, Starfire or Sunbird. Those are all H body GM cars and all used variations of coil spring suspension. Early cars used a triangulated 4 link and the later used two bottom links and a panhard bar, with a torque arm to the trans area. None used a leaf spring. Odd we can't ID this rearend...but in reality its the type of rearend we're more concerned with disposing of usually. This would have been pulled out and tossed for a 12 bolt, 9"Ford or even an 8-3/4 Mopar back in the day! LOL With the weak gearset, small axles and very high ratio...are you sure that rearend is stout enough for your project? That would be my big concern.
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