ive got a rearend that i was told was out of a 58-64 gm car. It looks just like a 9inch but little less beefy. i know nothing about this rearend except for ive heard they are relatively weak rearends. anyone have any info on them? thanks i appreciate it.
haha thats wut i was afraid of, its goin in my T, behind a 429 and a c6.... you know of anywhere that sells parts for em?
I've blown the spiders out a few times with them. The 55-64 is an early style 8.2, The posi type are a lil stronger. Just depends on what power you have. Good for cruzn.
Except the tri years are different from the late great years. Good luck finding a posi one......and those freaking wheel bearings on that rear are SO expensive. I've replaced both bearings and one axle on my 58.........but she's a total joy to cruise in.
It's the same rearend used in the Vette through '62 and IIRC the '62-'63 Chevy II. The difference between the solid axle Vette, the '58-'64 and the '55-'57 is minor and most parts interchange. It's not the HP that breaks them, it's traction. You can bust one with a 283 PG if you work at it hard enough. Trust me. A factory Posi will have a "P" about 3 inches tall cast into the front p***enger side of the center section. Parts are available but not necessarily cheap. An aftermarket posi is now available and the open housings can be easily modified to accept one if you're not doing a restoration and have to have the "Posi" housing with the big "P" cast into it. I'd sell it to a restorer or somebody building something with a bit less power and get something stronger. If it's an open it won't bring much but a good posi is worth a few hundred.
Almost everything for them is available at your local auto parts store. Cl***ic Industries for what isn't. Yeah, those outer axle bearings are pricey!
What is the lug bolt pattern diameter? I thought that GM had several different rear ends for those years.
The Chev rear is 4 3/4 bolt pattern, Olds, Pontiac, Buick, and Cad are 5". If the bolt pattern is 5", it's not a Chev rear and could be an Olds or Pontiac. Olds & Chev looked kind of the same(drop out 3rd member) in the 58-64 era, but the Olds is bigger and stronger.
You have officially fallen from my Christmas card list, and on to my I'm so jealous we'll never be friends list. I think I paid $120 per bearing? But I wasn't aiming to maim, just driving down the road when the original bearing gave out. Could you imagine trying to hot rod a 58 Chevy? Be like drag racing the ***anic.
One of the main caps is famous for breaking when power is applied--I think it's the driver's side... not because it's inherently weak, but because that's the side that takes the load when you dump the clutch. There used to be billet caps available, and racers frequently made straps that went over the cap to reinforce it and keep it from flexing. One of the axles frequently broke, and I think it was the same side, but don't remember now. Dana 44 limited slips used the same Posi unit, but machined for the Dana housing--it won't interchange. However, that's important because if you find an old Dana with 28-spline axles, you can take the spider gears from that limited slip and replace the spiders in the original limited slip, then get beefier 28-spline Moser axles, and you've eliminated a lot of your problems. It's still not a monster rear end, but it should hold up under anything light with 400 flywheel horsepower. And they look pretty good under an A. -Brad
60-62 Chevy C-10 trucks also had the rearend with the dropout center section. Here is what I found over the years before replacing mine with a 10-bolt. The truck rerarends are 6 bolt and completely round when viewed from behind. I believe the car ones are slightly flat top and bottom. Both posi and non-posi take 17 spline shafts, but they are different on the end just past the C-clip grove. The posi takes a smaller diameter shaft between the ends of the axles, therefore the shaft past the grove is twice as thick as the ones for the non-posi units. Driver and p***enger axles are different lengths also. I have a posi rear and can tell you that posi parts are not available for the truck units (at least that is my experience). The wheel bearings and seals are readily available. The axles are weak and easy to snap too, ask me how I know. As stated by Brad54, it was the driver side on mine that broke. Luckily, C-10 beds have skirted wheel openings that kept the wheel under the truck. The axles aren't available thru LMC either. Note: A non-posi axle can be used to replace a broken axle in a posi unit, if you tig weld a hardened washer of the proper diameter/thickness to the end of the shaft. The brakes are inadequate for a truck. These units are weak, lack parts availabilty, and have small brakes. Would be great though in a lower powered, light weight car such as T-bucket or a Model A.
I guess the stock posi in my 55 Chev didn't know it was weak. I drove the hell out of it and raced at Famoso strip with a radical built 327. I blew trannies but the original posi didn't break. I didn't have slicks but ran almost bald tires on the rear for giddyup. I still have extra 55-57 chev rear ends but don't recommend for torque monster big blocks, ecpecially in heavy cars.
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