Black Sunshine/ 00SS

Never heard of the rear, but a friend tells me that it is a rare option. Not a Ford 9", but it is supposed to be better than a 7.5. Made in Austrailia? WHat is the deal with the rear, & how rare is this? Gear ratio on this car with a 350, would be 3:50? My first 3rd gen. Please fill me in.

The cover doesn't look like the standard 10 bolt, it's different.

RedIrocZ-28

Harold, its called a Borg Warner 9 bolt. Count the cover bolts, if there are 9 then... well. The gear ratio's are as follows: 2.77, 3.27, 3.45, 3.70(I think). You probably got the 2.77's RPO G80. If you have a G92 car then you may have gotten the 3.27's or the 3.45's, it is doubtful though. 2.77's = Not good for racing. They are very expensive for new gears and carriers though. They are a tough rear end. There are guys running slicks on their factory axles still.

They are from Australia and I would seriously injure people for one. Mine was taken from me in an accident

Black Sunshine/ 00SS

So, if I decide to part the carout, it's safe to say you would want the rear then, right?

I know the original owner, and I can almost bet that there would be something around the 3:40 or better in there. I know the dealer where he bought it, so if I ever get it up & running, I'll do some research on the codes.

A friend who works at the dealer as a tech, says that it is very rare, and pretty strong. So, maybe slicks next year. For now, if it runs, it will be my winter beater, because some a$$ hole stole my truck...

irocbob89

The 9 bolt is a great rear end, i wish i would have stayed with it instead of going to the 9 inch. www.9bolt.com has some great parts for this rearend including new axles, gears from 2.77 up to 4.10's. Its alittle more expensive for this rearend but its worth it, its very strong and rare. The borg worner 9 bolts werent put in to many cars. Basically 87-90iroc-z's ever other fbody has the 10 bolt.

KeithO

In 1988, the 9-bolt was only available with a 2.77 or 3.27. If you go over to www.9bolt.com you can read an article on the strength of these units...

BTW - I have a 2.77 posi for sale on this site.

KeithO

Ooops. Forgot to mention - up until the 9-bolt was discontinued in 1990, the L98 f-bodies could only be ordered with a 9-bolt. The reason was that the 10-bolt (at that time) couldn't handle to torque (according to GM).

jayman350

I'm planning on getting my 9-bolt out of an 89 TTA (one of the other cars they were available in)

they are definately very strong rears, I can't wait to be able to use something other than street tires b/c I'm afraid that if I put even drag radials on my current rear end I'll blow it up

oh and I thought it was a 3:23 ratio and not the 3:27, probably wrong but now I know

KeithO

Breakdown of standard, optional and available 3rd gen rears are listed here:
http://www.thirdgen.org/newdesign/tech/techdb.shtml

Note that they change by model year. For example, the 89 TTA could only get the 3.27 from the factory.

The 3.23 gear ratio was for the later year automatic 6-cylinder 3rd gens.

aklim

www.9bolt.com claims they are more cost effective. However, they don't show what their setup is capable of supporting vs a Ford 9in. I am also somewhat skeptical because the 9 bolt was not very popular and so less were made which brings up the cost of the replacement parts or gears, etc. Anyone have any answers? TIA

irocbob89

If you have the money to buy a 9 inch then yes go with it, but think about it. How many times do you need to buy parts for your rearend? If you do a basic rebuild with the 9 bolt and throgh in some gears your rear end would be good up to 450hp with no problems im sure. Yes the parts for the 9bolt are more expensive and very hard to find but it sure beats paying for a 9inch, trust me

Black Sunshine/ 00SS

Now I'm wondering if the rear would swap over into a 4th gen? There might be an issue with the brakes, but woudln't the mounting points be the same? I know a guy who put a 98 rear in a 3rd gen, so there shouldn't be much difference.

Just what is the value of a rear like this, if I were to sell it? I didn't pay much for the car. It needs alot of things done to it just to make it a daily driver, and will most likely end up being a beater car.

Chris Ja

If you put the 9 bolt in a forth gen you would have the same problems as 3rd gens with what wheels you can use.
I have had my 87 IROC since new and only blown one ring and pinion. I have alot of mods and run BFG DR's. I used the DTS 373 gears which are stronger. They make more noise than the GM gears but like I said are much stronger. As I told you on the Mich board if you need any stock parts let me know I have a lot.

aklim

We do not sell complete rear ends at this time, sorry.

If you already have a 9 bolt, the upgrade package
consisting
of a new posi unit, 3.73 gear set and an installation kit
is
795.

Strength information is available at www.9bolt.com

The Ford 9 inch is much stronger, but also twice as
expensive

Thanks
Miles
Diff Solutions
www.9bolt.com

---- Original message ----
>Date: Mon, 16 Sep 2002 20:42:23 -0500
>From: Karen Sauer <karen.sauer@marquette.edu>
>Subject: 9 Bolt Questions
>To: miles@koolmeister.com
>
>
>I have a 92 Firebird with disc brakes. What would it cost
me
to get a
>complete setup with a posi and 3.73 gear so I could drop
it
in and it
>bolts up?
>
>How does it compare, strength wise to a Ford 9 in?

Rage

Yeah, hi, I have an 87 IROC Z. Does this mean I have the BW 9 bolt? If so, is it better than a 12? I dont know hardly anything about rearends, fill me in.

KeithO

The 9-bolt was an option for the 305 TPI, so it is possible that you have a 9-bolt. Get under the car and count the number of bolts on the diff cover - it there are 9 - you've got the stronger BW diff. If it's 10, you don't.

Interesting side note, when I drove my street legal, mostly stock 88 IROC at Watkins Glen in in May, I hooked up with an instructor with a full race prepared 89 IROC (this was not a street legal car). Not only that, I got to ride shotgun for 20 minutes while this guy POUNDED that track. He passed NASTRUCKS, prototypes, every car on the track. Sorry, I was getting excited again...

Anyway, he has a custom, built 380 ci motor (yeah you read it right) and he said that the ONLY thing that he didn't need to upgrade was his 9-bolt. It is that strong.