oxrabidus

i am about to build up a v8 for my camaro... and i have heard about how weak the stock rear end is... what exactly makes it weak? is it something that can be upgraded? im not looking to make gadgillions of torque just around 400 pounds... can the stock rear be upgraded to handle such amount? with some moser axles a positraction diff and some good rear end gears? or should i just get one from a 4th gen or something... thanks for the info!

AlkyIROC

The 7.5/7.625" ring gear and tiny pinion. All the upgrades to make it stronger can't fix the tiny ring and pinion. Fourth gen isn't much stronger since it uses the same 7.625" ring and pinion. It has 28 spline axles to your 26 spline axles but you can upgrade yours to 28 spline with the proper axles and carrier.

fast82z

iTrader: (1)

Don't know if I've herd of one particular weak point, more that the entire thing is just too small. You fix one weak point and find another, or just make enough power to have no strong point. I think the splines on the axles tend to go first, then followed by the ring/pinion.

oxrabidus

so what would be an affordable way to go, 9 inch rears aint cheap... and like i said, im not looking to make tons of torque... just around 400...
thank you

Kevin91Z

iTrader: (1)

For 400 HP, try to find yourself a 9-bolt rear end. They came on 85-89 f-bodies, mostly on 88-89 IROC's. And most of those are 2.77 ratio, so good luck finding a 3.27 or 3.45 ratio. Otherwise, you'll have to spend the money for a 12-bolt or 9-inch.

oxrabidus

i never heard of a 9 bolt rear... what diameter ring is that? and it wont matter what ratio it is i am going to rebuild it if i get it used...

Kevin91Z

iTrader: (1)

The 9-bolt is 7.75", but it has bolt-in axles without c-clips, and a cone-style posi.

Yes the ratio does matter, because it costs almost as much as a 12-bolt or 9-inch if you want to upgrade a 2.77 ratio to a 3.27 ratio or higher. The parts have to come from Australia.

oxrabidus

oh... damn... its gonna be pricey either way... how hard is it to put a 12 bolt rear from a truck in a third gen? ive seen those for relatively cheap...

Shagwell

The 12-bolt truck rears aren't that strong, although better than the stock little 10-bolt.

As for putting it in, very difficult. Our stock suspension utilizes a torque arm which mounts to the diff housing. Since there are no mounting provisions on any other stock type rear-end, it is very difficult. Since the housings are cast, welding any form of bracket to them is very difficult.

big gear head

If you plan on using the T5 transmission then it will probably break before the rear end. You are going to be making about 100 ft lbs more than the T5 can handle.

As for the rear end, the 9 bolt is the cheapest upgrade. If you get one you will need to find one with a 3.27 gear because the 2.77 uses a 2 series differential that won't accept other gear ratios.

How about this one? https://www.thirdgen.org/forums/engi...lt-3-27-a.html

oxrabidus

yeah i found one on ebay for about 100 bucks so far... and i can get it to me for about 230....just one problem... i dont have that kind of money now, and it seems like they dont come up that often....

transmission, i am digging either the super t5, which i have heard nothing but good about, or a TKO600, which i am digging more, because a blower may be in the later future... but thats later... if anything i have found rear ends from 4th gen LS, and LT cars, i have seen others push more through them, but i am not too sure... ive only read about it...

Stephen

iTrader: (12)

I've actually found more 3.27 9-bolt rears, than 2.77s or the 3.42s. 3.27 seems to be the most common 9-bolt.

One good thing about the 9-bolts, besides the bolt-in axles, not the c-clips of 10-bolt rears, is the disc brakes on them. Lots of 10-bolts with drums.

As for where to find one...All GTAs came stock with them & some IROCs/Z28s got them too. If you find a GTA, it has a 9-bolt.

oxrabidus

but how can you tell if its a 2.77, or 3.23, or 3.42? and how can it be made a bit stiffer?

big gear head

The gear ratio is the number of teeth on the ring gear divided by the number of teeth on the pinion gear.

Shagwell

Don't waste any money on a T5, if you must have a manual, step to a TKO or T56.

I too have found the 3.27 to be the most comon gear, but I haven't kicked up too many 9-bolts. You can build a 10-bolt to handle decent power, but by the time you wrap up the money in it you're ahead to save and swap to an aftermarket diff.

oxrabidus

well i was planning on doing aftermarket gears, c clip eliminators, moser custom alloy axles and a positraction differential... would that be good enough to handle 400 ft/lbs? and is there no way to tell from the outside what ratio... but its cool does anyone make a rebuild kit for the 9 bolt rear?

Stephen

iTrader: (12)

This EXACT SAME QUESTION is being covered another thread RIGHT NOW....as it is all the time. Nobody searches, they just ask.

loneroad

iTrader: (3)

check 9bolt.com

last time iwas on there he had new and used series 3 carriers.As well as gears 3:23,3:45.3:70,3:91and 410 or 411 (cant remember which)

HarmonyCamaro

what about the 3.73's?

big gear head

DTS had a very good installation kit for the 9 bolt. I don't know if they still carry it or not.

tony_cogliandro

iTrader: (3)

you can find 9 bolts for as little as 225.00 if you look. you can tell they are the posi units if they have disk breaks, that upgrade usually did not come unless you had the posi.
seek and ye shall find.

big gear head

The bad thing about the 9 bolt is that you don't know if the posi is worn out or not. The 9 bolt has a cone type posi that is not easily rebuildable. Pontiac
Posi Rebuilders in Ohio has a way of fixing them, but I don't know what the price is. Just be carefull if you buy one and be sure that the posi is still good.

oxrabidus

i just chcked out 9bolt.com and they sell brand new series 3 (what that means... i dont rally know... if someone can tell me it would be cool...)... its 550 but that is the price of a aftermarket posi anyways, and i was planning on getting one so that was already fitted into my budget... i just gotta wait a little while before i can actually start looking for the whole rear... and i would like to get new axles and such... make sure its nice and spiffy...

big gear head

3 series means that it accepts gears of certain ratios. A 2 series takes the 2.77 gears and a 3 series takes the 3.27, 3.45, 3.73 and so on. The difference is in the location of the ring gear flange. The flange of the 3 series is located closer to the pinion center line than the 2 series.

These are Eaton posi cases for the Chevy 12 bolt car rear end. The one in front is a 2 series. Notice how the ring gear flange is offset as compared to the 3 series next to it, and the 4 series in the back.

oxrabidus

ah i see... so the series 3 would be the one to get... looking at prices its gonna cost me slightly less than a 9 inch case without the innards... so around a grand... whoa... but better than 2 grand eh... thanks for the help it is greatly appreciated!

Shagwell

That should be enough, but at that point you've spent atleast half what a 12-bolt or S60 swap would cost you. Too each their own, but IMO if it cost me half or more of the higher level/new part to upgrade/fix what I have, I hold off and spend the extra $.

HarmonyCamaro - he listed the 3.70 ratio, I believe there is now a company producing a 3.73, but if you think you'll notice a difference in .03 you're nuts.

I don't know of any aftermarket axles available for the 9-bolt, but others probably know more than me on that. - Remember, it'll still never be as strong as a good 12-bolt/60/9".

oxrabidus

this is very true... but, i am just starting this project... and it is a "rolling project"... my funds are not that great... i cant afford to have it sitting and such for too long, i wont be making that much torque... im building a 305, so 400-450 pounds may be optimistic, it will be a pretty stout 305 (at least i hope...)...in fact it probably is... but i would feel good knowing that what i have will be reliable...and from what was said, if i can get a 9 bolt it will do me just fine... and if i had money/time (i am making the wife angry with a motor sitting in the back porch, hahaha...) i would get the best of the best, we all would... i dont wanna sound like an *** or nothing, you know...

loneroad

iTrader: (3)

call or email hawks, When i was originally looking for one they had alot of em. no where near a grand. This wads a few years ago.make sur you tell them what ratio and series carrier your looking for.

loneroad

iTrader: (3)

also wherever you get it, if it comes w/ disc brakes, make sure you ask for the proportioning valve for the brakes

oxrabidus

i will probably buy a new master cylinder and prop valve for the brakes, i would love for my car to stop better... the brakes on in now are kind of weak, maybe worn parts... but i will just go ahead and get new aftermarket pieces... and i dis check hawks, and they were selling used ones for 500 dollars... i will keep looking for more affordable ones and rebuild them... i dont like buying from hawks, they sold me the wrong parts twice now...

Shagwell

I understand where you're coming from.

Another note, even if you get a disc rear and a new prop valve, shimming the rear side of the prop valve will greatly help your braking abilities. Many of the disc cars actually won't hold the rear tires; in gear, on jack stands, at an idle. GM really didn't put enough pressure to the bak on these cars. - The info about shimming them can be found from a search.

oxrabidus

i will do that, would it have to be done even with an aftermarket prop valve, or are there any aftermarket ones?

and i always thought my rear brakes were really crappy, since i could do crazy burnouts (one wheel of course...) with my little 2.8... with two, it could do it, but not for long... not long at all actually...

Stephen

iTrader: (12)

It's funny how the earlier rear brakes have always been "dogged".

My 87, with the Delco calipers on the 9-=bolt, vs the PBR calipers on 88+ 9-bolts, does VERY well.

At 60 mph, I can jump on the brakes & lock all 4. I discovered that when Bambi ran out in front of me one night.....

Not saying everyone is wrong or crazy....I expected mine to be no good when I bought the car 3 years ago, but have never complained once, about weak brakes......

Shagwell

My '89 GTA with the stock PBR rears wouldn't hold the rear tires from turning on jack stands at anything over an idle. If you thought you tapped the gas they wtarted slipping through the brakes, even after driving the car to be sure everything was up to temp. - 3 shims solved that. Major difference ins stopping distance. We did the same to a friends '87 when he went from the old-style disc to the PBR's. The PBR system was better than his older style, but not nearly like a shimmed set-up.

The only "aftermarket" prop valves I know of are the in-line adjustables. if you go that route you can tune the bias however you want/need, but you should eliminate the stock type valve completly.

My car still did brake-holds fine, but all in all if that's what you want to do you should really invest in a line-lock.

oxrabidus

line locks... does summit sell them? and i would need to eliminate the prop valve to use these? is it one per wheel or one for the back and one for the front?

tony_cogliandro

iTrader: (3)

thank you for that information. i love to read these boards, i never come away without learning something.

big gear head

You're welcome Tony.

The line lock goes between the master cylinder and the prop. valve. You only need one. This is an electric one way valve that holds line pressure on the front brakes as long as you hold the button. You just push the button and pump the brakes a few times and the front brakes will stay locked until you release the button.

loneroad

iTrader: (3)

this is the one I use. 0 complaints. summit# SLE-24048.. Also as far as strength goes, check oit TA performance. They sell a girdle for the 9bolt rearend.

oxrabidus

fantastic... i will definately get that... so shim the brakes for more pressure at the rear, and get the line locks to be able to do a good burnout at the track? yes... sounds good...
and the guy at 9bolt.com said that the 9 bolts can handle 500 and somtimes more torque... with 28 spline axles... and the 31 spline over 500 surely... so i would feel good knowing this... i will probably get a good brake system as well...

Kevin91Z

iTrader: (1)

89+ rear ends have the PBR brakes. 88 and earlier are the iron brakes.

Pump the brakes first, hold the pedal, and THEN push the button to lock the front brakes. If you push the button first then the gate in the line lock keeps the fluid from reaching the front brakes. Push the pedal and hold it, then push the button. The gate comes out inside the line lock and keeps the fluid from coming back away from the front brakes until you release the button.

Stephen

iTrader: (12)

Typo...My bad. I KNOW the difference, just typed wrong.

big gear head

My Hurst line lock works if I hold the buton and then pump the brakes. It's a one way valve. It allows fluid to flow in one direction but not the other.

Shagwell

If I had to pump my brakes to do anything other than bleed them I'd be scared.

Yes, step on the brakes, hit the button, release the brakes. The fronts will stay held until you let go of the button. - big gear head is correct, some line-lock/roll-controls utilize a one-way type solenoid valve, thus you can hit the button then press the pedal.

big gear head

You just pump it to build more pressure when using the line lock. It's actually not necessary, one push of the pedal will do it. It doesn't affect the operation of the brakes in normal use.

subroc

iTrader: (2)

Unlike me. My posi is on its way out. Thats why the rear is in my garage taken apart. Pontiac posi rebuilders charges around 135 to redo the posi unit. Im going to "attempt" to do it myself. I found a good how to article on it on this sight as well as a PDF online showing step by step pictures. So yea even i can follow directions lol.

tony_cogliandro

iTrader: (3)

how about posting the link to the site where you got the pdf?

big gear head

I'd like to see that too.

blackroc68

iTrader: (2)

Not true you can buy gears made by yukon,precision.and maybe Motive.Randys ring and pinion has everything you need for the rebuild.

subroc

iTrader: (2)

Sorry for not including the link. I for the life of me couldnt find it upon researching so, since i had downloaded it, i looked at its title and found it once again. Its not labeled very well to help people find it.

http://www.geocities.com/luckyducky_...air30Nov04.pdf

Enjoy!

This should really be added to the tech articles on this sight or made a sticky