School me on S-10 rear ends!

[Levis Classic]

I have talked to many folks lately who are using S-10 rear ends under their T buckets or roadsters.

Not exactly traditional but who can tell me what to look for with these rear ends. 2 wheel drive verses 4 wheel drive and are there any with posi's and how about gear ratios?

[Unkl Ian]

4WD is probably too wide.

[Fat Hack]

I think 4x4 ones are wider...positraction was available as an option...a few ratios were common...3.08, 3.73 and 3.5, if memory serves.

(I think some 4x4 models with the 2.5 motor had 4.10 gears)

[Ayers Garage]

some had 2.73 gears too, so check carefully.

[JimC]

I have one in my 32.
Do not know the ratio, but it must be high since the car drives well on the interstate.
It is narrow for the wheels that are on the car so there are spacers to get the wheels away from the body.
I did not build the car, so can not offer much more than these observations.
I will look tomorrow to see if the id tag is still there and if it has the ratio.

[Bass]

I have an S-10 rear under my shoebox... here are a few facts:

*These are 10 bolt rears with a 7.5" ring gear, and 4.75 inch (GM pass. car) wheel bolt pattern. Axles are retained with C-clips.

*2WD rears measure 47.5" between backing plates, 54.5" from outside drum to outside drum, and approx. 38.5" between spring perch centers.

*4WD S-10 rear ends are wider than 2WD by about an inch per side.

*82-88 rears had 26 spline axles...89-up used 28 spline. Therefore, to interchange carriers between early and late rears, axles must also be changed, and vice versa.

*Quite a few of these rears were equipped with factory posi-trac.

*There were a wide range of gears available. In my opinion 3.42 and 3.73 are the best for all around street use in most cars.

*There is a code stamped into the passenger side axle tube that will tell you application and gear ratio by cross referencing the first 2-3 letters of the code in a Hollanders Interchange Manual.

*S-10/S-15 Pickups and Blazers have identical rears. I've also been told that Astro van used the exact same rear. Some later rears were equipped with disc brakes.

*These rears will stand up to serious street abuse in most cases....well, mine has anyway. (knock on wood!)

Hope that helps!

[Levis Classic]

Thanks Bass!

[Hot Rod To Hell]

[ QUOTE ]
*These rears will stand up to serious street abuse in most cases....well, mine has anyway. (knock on wood!)


[/ QUOTE ]

I wouldn't bet on it.
The 7-1/2" 10 bolt is the biggest POS rearend GM made as far as Hot Rods go. I had a 78 malibu with a mild 350, and those cars come with the 7-1/2" rear as well. It wasn't anything serious, just a 13.90 car (3000 lbs), and I was breaking the rear ALL THE TIME!!! http://www.jalopyjournal.com/ubbthreads/images/graemlins/mad.gif

In the 2-1/2 or 3 yrs I drove it I broke: 3 factory gear sets (stepped up to a richmond and had no trouble), 2 GM posi units (stepped up to an auburn, and had no trouble, but the kid I sold the car car to killed that one too!), and 3 axles (I never dropped the dough on good axles). http://www.jalopyjournal.com/ubbthreads/images/graemlins/crazy.gif

So think twice before you put any power to it! http://www.jalopyjournal.com/ubbthreads/images/graemlins/crazy.gif

[Fat Hack]

Ha Ha Ha, hey Steve...you sure you ain't related to a guy named Dave Terry? He could make a Dana 60 explode just by walking to within a hundred yards of it! Never saw ONE guy trash so many rear axles!

(In like STOCK beaters, too...as well as his hot rods!)

I remember the time he grenaded the rear axle, driveshaft AND transmission in one shot right in front of my house...he had a beat up 77 Caprice Classic that I agreed to buy off him...so he goes to drive it home to pull his stereo and nitrous bottle (yes, NITROUS BOTTLE!) out of the car before we do the deal.

Bonehead floors the pedal in reverse outta my driveway, nails the bottle, then slams it into low with his foot still on the floor and the bottle sprayin'....makes it maybe five houses away doin' a John Force style burnout when the thing free-revs to like eight grand and parts and fluid go everywhere! The driveshaft trashed the whole underside of the car before shooting off onto one of my neighbor's lawns...ripped the exhaust off and everything!

I had to tow Dipshit back to his house, and he spent the next day installing a new rear axle, trans, driveshaft and a set of headers with duals to replace all the shit he broke! (His girlfriend's brothers all worked at a junkyard...hooked him up!) Then, I actually went ahead and bought the car from him! I did some insanely crazy things with that car...but never broke a thing...305s RULE!

(I'll have to tell you about that car's encounter with...ummm...a...uhhh...white Crown Vic sometime...while Dave still owned it and I was riding shotgun praying for dear life...fuck, Bo and Luke shoulda used a 77 Caprice...I can attest to their flight capacity and sudden off-road ability...ol' 'Rosco' couldn't fly!!!)

[Bass]

When I say it will survive on the street "in most cases"...that doesn't mean it's going to hold up to wheels-up launches at the strip or serious HP...or even a healthy shot of nitrous.

But I've done some crazy shit in a 4000lb car with somewhere around 300HP (conservatively) and a 4spd, and I'll vouch for their strength in street applications. In fact, the rear's one of the only things I haven't broken yet. (Knock on wood again!)

If you're going to spend the money on a motor that's capable of big HP or a chassis that can hook up hard...then you should be sharp enough to plan on eventually stepping up to a 9 inch ford (or equivalent) anyway.

However, in a light car I believe that the S-10 rear would hold up to close to 400HP and still live for quite a while. The later 28 spline axles would help too. Just don't make the mistake of thinking these rears are bulletproof. http://www.jalopyjournal.com/ubbthreads/images/graemlins/wink.gif

[lesabre59]

Hey BASS..have you ever dropped a Powertrax unit in one? I have a S-10 rear in my A and i'm fixing to add the Powertrax, just curious if it added any strength with this unit or just a posi conversion?

[Hot Rod To Hell]

I have the powertrax unit in my 8.5" 10 bolt, and I dig it. No parts to wear out, and you don't have to mess with any of the shims in the rear (as long as you're not changing gear sets). Seems pretty well built as well. I don't think I'll ever put another clutch-type posi in anything I build!

[lesabre59]

Did you have any "posi clatter" after installing it?

[kustombuilder]

had a friend with a low 13 second V8 S10 with a stock rear, he abused the hell out of it on the track and on the street and held up for quite some time (a couple summers if i remember right), then he finaly spent the dough on an Auburn posi but left the rest stock.

[kustombuilder]

oh yeah, he was running a 10" slick most of the time.

[Hackerbilt]

The ones I've seen had LOCKERS, not clutch posis.
When they are out of the car you can spin one axle with your hand and the other won't spin...until you hit a certain speed where they lock with a solid clunk!
It's that solid clunk that kills when they have serious HP running thru them. There seems to be no cushioning between open and locked up.
I'd use one in a simple "driver"... but I'd be wary of adding gobs of power!

Bill

[Deuce Roadster]

http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif


A lot of them are noisy.........the early ones more so. Noise may not be a issue in a closed car........but in a open car, you HEAR everything http://www.jalopyjournal.com/ubbthreads/images/graemlins/smirk.gif

I believe the gears were cast not cut..........I have been told.

When I worked at the junk yard, we sold a lot of them to go back under S10's as replacements.



http://www.jalopyjournal.com/ubbthreads/images/graemlins/crazy.gif

[Hot Rod To Hell]

[ QUOTE ]
Did you have any "posi clatter" after installing it?

[/ QUOTE ]

You get that nice "click-click-click..." going around a corner, IF you're coasting... Under power it won't even unlock and you'll just spin the inside tire!

Make sure you're totally straight when you nail it though, or you'll be facing the other direction in a hurry!!! http://www.jalopyjournal.com/ubbthreads/images/graemlins/crazy.gif

But when you DO nail it, it's just like you've got a spool... full power to both wheels! http://www.jalopyjournal.com/ubbthreads/images/graemlins/cool.gif

[lesabre59]

Does it make a difference if you run Royal Purple gear lube or any kinda synthetic??

[SpeedRacer2002]

i had about 345 horse motor with a 250 shot of nitrous in my old S-10 and never blew out a rear end....

[Rocky]

I inadvertantly bought one of those at a swap meet last weekend. I was told it was an 8.2" posi from a 71 malibu. I bought it for a guy at work needing one for his 72 Malibu and this one turned out to be from a 79 malibu, so it's a 7.5"posi with [gulp!] 2.41 gears. It's be great for my v/8 astro van with the hiway gears and I need a posi for winter anyway. This one has a clutch-type posi.

[Hot Rod To Hell]

I've never tried anything in it other than some regular old 80/90. Synthetics, or thicker oil might make a difference...

[Rocky]

Like Bass, I ran one in my hot rod for about 2 years with no problems. [came from a 83 gutlass donor car] It was a 33oo lb 50 chevy sedan delivery with a 406 sbc, 12 inch clutch and a saginaw 4 speed. I never put it on the strip or ever ran slicks on it...used BFG 285/70R15 radials and I usta beat on that poor car. It never broke except for the reverse idler in the tranny. However! I sold it to a guy that beat on it a little bit harder than I did but the rear end stayed together...it was the saginaw that 'sploded...

[Hot Rod To Hell]

Alright then, so are you guys really lucky, or am I really UNlucky??? http://www.jalopyjournal.com/ubbthreads/images/graemlins/crazy.gif

Don't bother answering guys...

If it wasn't for bad luck, I wouldn't have any!!! http://www.jalopyjournal.com/ubbthreads/images/graemlins/crazy.gif

[lesabre59]

HRTH..i'll be hitting the road in the next couple months with the Powertax installed..I'll let you know how it holds up with BFGoodrich 30" drag radials http://www.jalopyjournal.com/ubbthreads/images/graemlins/cool.gif

[fab32]

The experience I've had with these rearends consists of an S-10 Blazer, factory tuned port 400 with 350hp cam, 700r4 with a shift kit. The rear is a 3.73 posi (factory stock). I've put 60,000+ mi. on it and haven't babied it at all. The last time I had the rear cover off I could see some evidence of cracks in the ring gear teeth, the same cracks that were there after 10,000 miles and didn't seem any worse. Now to qualify this, there has never been any slicks on this car and I've only neutral launched it a couple of dozen times (in 4 wheel drive) so I don't think it has been subjected to any real abuse.

Frank