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Old 07-29-2007, 07:03 AM
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Is a 7.5" rear worth the hop ups?

Hey- I just got my V8 s10 running and I'm kinda worried about the rear end. It's an '85 model, so it's got the 7.5" w/26 spline axles, open carrier.

I'm just wondering if it would be worth it to weld the axle tubes, put in a set of gears, a limited slip- or just try to find an 8.5" from another s-series, or an 8.8 from an explorer??

The 8.5 is pretty much bolt in. And the 8.8 goes in without much trouble- fairly easy swap. Might could get lucky and find one at the pull-a-part.

Is the 7.5 worth the money and effort, or would I be better off going with a beefier stocker?

Nooj

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Old 07-29-2007, 08:55 AM
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good luck trying to find a 2wd 8.5. go with a 8.8 if you don't mind have a ford rear. the 7.5/6 can hold up, sometimes. but its a crap shoot. if you have an auto trans, a support cover, and street tires(not ET STREETS either). it can last, mine is.
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Old 07-30-2007, 03:51 PM
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The 7.5 will last as long as it is open (no traction). Any bite with this or a posi will blow it up
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Old 07-30-2007, 06:48 PM
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no true. i have a posi....

the thing is, you can't beat on it. sure, i get on it. but i don't do many burnouts and no donuts. hooking hard is what kills em. drop the clutch at 5000rpm and a good chance = boom. i have an auto trans and T/A radials.
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Old 07-30-2007, 07:37 PM
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Quote:
Originally Posted by lumberjacknooj
Hey- I just got my V8 s10 running and I'm kinda worried about the rear end. It's an '85 model, so it's got the 7.5" w/26 spline axles, open carrier.

I'm just wondering if it would be worth it to weld the axle tubes, put in a set of gears, a limited slip- or just try to find an 8.5" from another s-series, or an 8.8 from an explorer??

The 8.5 is pretty much bolt in. And the 8.8 goes in without much trouble- fairly easy swap. Might could get lucky and find one at the pull-a-part.

Is the 7.5 worth the money and effort, or would I be better off going with a beefier stocker?

Nooj
v8 s10s are all ive had the 7.5 rearend 26 spline or 28 have held up with a locker differential. ive yet to break one, but i havent used drag slicks though.but it would still hook, i also seen alot of 8.5s in fullsize trucks explode. in my opinion the 7.5 is stouter than an 8.5
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Old 07-31-2007, 10:11 AM
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Thanks for the replies, fellas. I think I've heard enough positive testimonies for the 7.5" that I'll just use the one I got. If it ain't broke don't fix it, right? Well... fix it a little so it don't break, I guess.

I'll probably try to find a used locking diff- maybe one of those zexel-torsen ones from the f-bodies, a set of gears, and maybe a support cover... That oughta do it. I hope

Thanks again for the input, guys.
Nooj
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Old 07-31-2007, 11:15 AM
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[QUOTE=lumberjacknooj]Thanks for the replies, fellas. I think I've heard enough positive testimonies for the 7.5" that I'll just use the one I got. If it ain't broke don't fix it, right? Well... fix it a little so it don't break, I guess.

I'll probably try to find a used locking diff- maybe one of those zexel-torsen ones from the f-bodies, a set of gears, and maybe a support cover... That oughta do it. I hope

Thanks again for the input, guys.
Nooj[/QUOTE

if you worry about it breaking, it probably will. if you dont give a schit wether it does or not, it will last forever.
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Old 07-31-2007, 01:10 PM
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Its pretty widely held amongst hotrodders that the 7.5 rear is not a great choice for any performance vehicle. I've personally seen several of them grenade behind motors that weren't that wild (sub 450 horse motors). Sure, it depends on hook-up etc. I don't know what you intend to do with this car, but for my money a rear end is kinda worthless if its killing your 60' times because you can't afford to put the coals to it until you're already rolling.

I'd also say that the "wait and see" philosophy isn't a really good choice. You can break a rear end and be lucky, the best that happens is you have a little unexpected work and some expense. Of course, you could also grenade the thing and lose control of your vehicle, or get some damage to your car.

A more stout rear isn't a huge investment. In all honesty it would probably be the first thing I'd get for any performance vehicle. No sense in doing work twice or risking safety-

K
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Old 07-31-2007, 08:45 PM
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The hop-up parts for the 7.5" will cost the same as ones for the 8.5", and it will break a lot sooner. A used 8.5 might cost you a hundred or so, and after you spend a few hundred more on it, you won't have to worry nearly as much about having to walk home.

GM used the 7.5" rear behind the anemic 2-bbl 305 for only one year in Novas, then went back to the 8.5" from then on. What does that say about the durability of a 7.5" rear?
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Old 07-31-2007, 09:14 PM
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Some pretty good info in here... I'm also looking for a little advice..

What do you guys think about used lockers/posi's???? (8.5 10 bolt)
Seen a bunch on eBay, and just missed out on a cheap brand new posi at a swap meeet, and I'm looking to start building my 8.5 soon....

What to look for? What to avoid???....
thanks

eazy
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Old 08-01-2007, 12:52 AM
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7.5 rear worthless

Stay away from what is known as a Gov-Lock differential in the 8.5 rear, seems like they explode just by looking at them. Easy to identify by the big square block between the side gears, where a normal Posi has two plates w/ several springs between them.
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Old 08-01-2007, 07:33 AM
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Quote:
Originally Posted by ericnova72
Stay away from what is known as a Gov-Lock differential in the 8.5 rear, seems like they explode just by looking at them. Easy to identify by the big square block between the side gears, where a normal Posi has two plates w/ several springs between them.



any more info on buying a used locker/posi???
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Old 08-01-2007, 11:39 AM
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7.5 rear

Easy-- that photo you posted is the one to stay away from. They frag the shaft with the flyweights on it, usually at its driven point.
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Old 08-01-2007, 12:29 PM
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Quote:
Originally Posted by ericnova72
Easy-- that photo you posted is the one to stay away from. They frag the shaft with the flyweights on it, usually at its driven point.
Thanks for the tip, how about the stock type ones(S "spring") vs the coil spring loaded?
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Old 08-01-2007, 12:48 PM
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7.5 rear

8.5 rear diff with an s-shaped spring is an Eaton and is rebuildable. Of the two-plate-and-coil springs versions, there are two types. If the case is a one-piece forging, then it is updated or aftermarket Eaton version- also rebuildable. If the case has a bolt-on end cap on the pass. end then it is Auburn and has cone clutches and is NOT rebuildable.
Other things to watch out for are whether case is two series or three series(2.56 and down or 2.73 and up) and axle spline count(28 or 30)
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