Hey guys I need some advice, I got a 9-bolt posi out of a 87 Trans-am. After getting it home and working on it I found out that it was a 3.08. Believe me, it even had the tag on the rear end cover. I need a 3.73, the 3.08 is awful. Can I get gears for it, I am betting no because it is probably not a 3 series carrier. I have an 86 IROC that came out of my car, it was originally a 2.73 and I put a 3.73 Richmond gear. But it is an open rear end. I know my options but, do I want to deal with a posi that sometimes doesn't lock up around corners, even my new 2002 Z-28 3.42 Auburn posi does that. I think that I want a Powertrax locker, what do you think? Does it really make a bunch of noise around corner? Do they last when you drive them on the street? Let me know what you all think.

 

www.diffsolutions.com

 

Although the 9 bolt is better than a 10 bolt, performance options are limited. I doubt you'll find a powertrax for a 9 bolt.

You can also try www.9bolt.com

 

Just for the record, www.9bolt.com = www.diffsolutions.com

 

I have a posi 9 bolt but I want a 3.73 ratio. That is the question. The locker is for the 10 bolt but I would like to hear what you guys think about them.

 

Does anyone have any feedback on the lockers for the 10 bolts? I talked to Miles and he thinks that there is no way he can do anything for my 9 bolt. 3.08 sux for acceleration and when your shifting at 7500 rpms, it makes for long gears and a top speed, if there was any way in the world, of 227 mph... I have a 3.73 for my 10 bolt. Anyone used a locker?

 

WHAT!!! When did I say that?

3.73's for a 9 bolt are no problem. I can ship it tonight. All you need is a series 3 carrier.

As for a locker type unit, the closest I can come is a mini spool for the 9 bolt, but it is not recommended for street use.

Miles
Diff Solutions

 

I am the one that you sent some emails to a couple of months ago. Since then I have done lots of stuff, but I thought you said that I can't run that 3 series carrier in my 2 series carrier. I haven't taken it out yet but since it is a 3.08, well you know. Am I wrong? Can't imagine that

 

ok sorry, and yes you are correct. You can not directly fit a series 3 gear onto a series 2 carrier.

At first I thought you meant I couldn't get you a 3.73 gear set for a 9 bolt (series 3 of course)

Miles

 

Can I switch carriers to a 3 series, then get 3.73s? That is probably expensive though if it is possible. What do you think?

 

I Don't believe you,...........


I have NEVER heard of a 3.08 gear from the factory in a 9-bolt. Even the ThirdGen Tech section supports my theory that your rear is NOT a 3.08 9-Bolt.

HyperLink to Tech Section


Let me know what you have after you count the teeth !!!

(It's REALLY easy to stick a tag on the rear end cover !!)

 

https://www.thirdgen.org/techbb2/sho...highlight=3.08

https://www.thirdgen.org/techbb2/sho...highlight=3.08

https://www.thirdgen.org/techbb2/sho...highlight=3.08

https://www.thirdgen.org/techbb2/sho...highlight=3.08

https://www.thirdgen.org/techbb2/sho...highlight=3.08

https://www.thirdgen.org/techbb2/sho...highlight=3.08

https://www.thirdgen.org/techbb2/sho...highlight=3.08

https://www.thirdgen.org/techbb2/sho...highlight=3.08

https://www.thirdgen.org/techbb2/sho...highlight=3.08

I"ll continue when i get back from dinner

or u can just search urself.. and see how many other people have 9 bolt 3.08 rear ends....

 

Actually, the 9 bolt was first availiable in 85, so most of the links have no merit. The 10 bolt cars did come with 3.08's, I currently have three 9 bolt rearends in my garage and ALL are disk rear and NONE are 3.08, they all came off of 86 Trans Ams. I have yet to see a Camaro with a 9 bolt.

 

not to say anyone is wrong here BUT 3.08 is a common ratio in aus ...maybe some made it out to usa ...same as the 9 bolt with drum brakes !

 

half those links talk about 9 bolt 3.08's... so i don't understand what you are saying..

 

I looked at all your links too -

the only referance made to the 9 blot 3.08 gears was from a guy that thought he was driving a 1983 IROC < No offense "Kingtal0n
" >.

Several links you provided give the codes or choices for 10 bolt 7 1/2 (or) 7 5/8 gearing.


Not meaning to bust your ***** here ------- just waiting for REAL proof.

P.S. I also have 3 9-Bolt rears and none are 3.08. The one pictured is a 3.70 (aftermarket gears) & Yes,...... it's a Camaro !! The Original gear sets for my 9-bolts were 2.77, 3.27 & 3.45.

 

Here this is right from diffsolutions.com:

"Common factory ratios were 2.77, 3.27 & 3.45, uncommon factory ratios are 3.08. After market ratios are 3.70. Ratios that I offer are 3.23, 3.45, 3.73, 3.9 & 4.10 (actually 5.13 but bring your visa card, and 3.9 is special order)."
this might clear some stuff up.

 

Thank you. I am very sure that I am the first one to open this rear end and no one switched the tags on it and even if they did, It says borg warner and the 3.08 ratio right on the tag. Trust me IT IS A 3.08 9 BOLT. I checked rotations even and there is enough of a difference to see 3.08 and 3.27. I really wish it wasn't a 3.08 because I am running about 55 mph in first gear, when shifting at 6800.

 

The attached pic is of the gears inside of a non-posi, drum, 3.08 9 bolt. If you look close you can read the BW 2 3.08. It is a borg warner rear with series 2 carrier and 3.08 gears.

Ben

 

Another showing the drums.

Ben

 

That goes against everything I ever saw on the 9-bolt.
Drum brakes, non-posi and until recently, 3.08.
These were always: 2.77, 3.27, 3.45 with locking carrier and only disc brakes. Almost forgot - 3.70 too.

Does anyone have an extra 3.08 gear set they are willing to part with? Let me know.

 

Same here dude,.......!

If the pictures are true than I guess that rear end is simply a freak !

 

Almost always Plus, there is now an aftermarket (finally) for 9 bolt parts, me Ratios to 4.10, posi units, mini spools, and coming soon - rear girdles, steel caps, solid pinion spacers, etc..... It's all at www.9bolt.com

PS The differentials are posi (aka limited slip, or what ever you want to call it), but they are not "locking" carriers.

Miles
Diff Solutions
www.9bolt.com

 

Were the 9-bolt 3.08 setups in Chevy, Pontiac or both?
What years?
What engine and transmission combinations?
When was this 3.08 setup used as opposed to the 10-bolt?

 

The one I posted a picture of above with the drums and 3.08 gears came out of an 85 trans-am. Stock the car had 15" wheels. It had I believe both the fe2 and f41 suspension options. It was an lg4 automatic. It pisses me off everytime I think about it, but it appears I misplaced the rpo sheet. Oh, well I guess. I think the car has more stuff that wasnt on the rpo sheet than what is now.

Ben

 

Just to add support for the 3.08 9 bolt. My dealer order sheets show the factory diff on a 1989 T/A with the 305 TPI 5speed to be a 3.08. Only the GTA with the 305 TPI 5 speed got the 3.45's.

This was news to me to, as I just bought a 1988 TA with a 9 bolt disc rear in it. I was hoping for a 3.45, but now I suspect 3.08's.

Mark.

 

The BW non POSI is a freak ---

The BW with Drum brakes is a freak ----

The BW with 3.08's is a freak ----

I have a feeling this car was imported from another country or something weird like that !!!!



Mark - the "build sheet" proves that the dealer sold an 89 3.08 rear end in a 305 with a manual tranny. That can not prove that the car was a 9 bolt rear end since the stock gearing for the 89 305 TPI Manual cars was 3.08 (10 bolt).

Your car ( the 88 / Auto ? ) probably has the factory 2.77 gearing unless you have the Optional G92 code. If you have the G92 code than the 3.27's would have been installed.

 

John,

My opintion, in the pontiac line, GM was nice enough to package things, unlike the camaro where there was a performance axle ratio option. Typically when you got the WS6 suspension, you got the 9 bolt BW and yes it was often a posi.

I'll know soon about the 88 T/A. I know it's a BW posi disc rear end. The ratio I am expecting to be a 3.08 based on the GM order sheets because you could not get a 10 bolt with the WS6 suspension in 1988. If it is a 3.45 ... great news for me. But my thoughts are that it will be a 3.08.

The 88 is a 305 TPI, 5 speed, WS6 suspension. Your basis T/A with a TPI in that year which says it should be a 3.08. Only the GTA and formula got the 3.45 ratio with the 5 speed TPI ... according to the order sheets at least.

Another odd car in the years when GM did strange things.

I don't think anyone can say for sure what GM did. There was many common things, but there were those odd cars ...

Mark.

 

Let us know when you find out, Mark.

 

In a Pontiac, the G92 (performance axle ratio package) was a race package similar to 1LE. I believe it started '91 or '92.

Momar, what is the RPO listed in that '85 for the axle? Also, do you have the code stamped on the axle tube?

'85 makes sense for the 'freak' arangement. The first year for the 9-bolt. GM was probably thinking at that time of totally converting over to the 9-bolt if everything worked out.

 

Would you believe the car came with 3.70's?!?!?!? I figured that 305 had lots of pickup, so we jacked it up and check the gears. 3.70's add that to disc brake, posi and BW ... it is a great find. YEars ago I would have loved to find this deal. It's a shame I don't have a use for the diff.

IT's for sale as are other parts on the car. I would like to sell it locally to save the hassle of shipping, but if there is someone in need, we can see what can be worked out. I don't even know who to call to ship something that big.

BAck to the 3.08 debate. My papers show 3.08 as a gear ratio in a TA wiith a 305 TPI 5 speed and I was quite sure you got the BW rear with a TPI in pontiac. There must be 1987/88 TA's out there with 305 TPI 5 speeds. Be worth polling to find out what they have for option codes.

MArk.

 

As I mentioned, I dont know where my rpo code sheet is. I was not able to tell what the axle code was while in the car and after I took it out I didnt care because I knew what it was. I would look, but it is burried in the back of my garage. The car now has 3.45 disk 9-bolt.

Ben

 

BURRIED! Oh, come on. There are hundreds of people on this board that are willing to tell you are full of **** and you pass on the chance tell them were to stick it by supplying a couple of numbers. I personally am not trying to call you on it. I can believe the setup, but you have to admit that saying you lack interest looks like you are dodging something.

 

Dodging something my ***. Did you look at the pictures I posted earlier in this thread. It is a picture of the rear with drum brakes and one with the cover off and the ring gear has BW 2 3.08 stamped on it. I dont have those gears or carrier anymore because I sold them to the guy that bought my 2.77 posi disk rear, but I still have the housing and axles. You may want me to try to find the axle codes but you cant say I am dodging something when I already posted pics that prove what it is.

Ben

 

Again, I am not saying that I don't believe this arangement. I am just pointing out how easy it would be to not believe it when no one is willing to post some codes. Your pictures are nice but only proves you took pictures. Take any 9-bolt rear, turn the gear to a bare spot and strike in some new letters with number punches and a heavy hammer. The other is just throwing some spare parts together, doctor them to look original and say "see." Not accussing you of doing this but pictures just can't be as convincing to non-believers as code numbers they can look up and start the researching.
My personal interest in all this was to find when this setup was available. Years, models, drivetrains, etc. Definately seems rare. Maybe it was a Canada car setup. There just doesn't seem to be much info available on it.

 

Well, you know honestly I dont care if you have proof if you wont even take my word or pictures. How do you know I couldnt forge the axle codes just as easily as I supposedly forged the numbers on the ring gear. Go here www.picturetrail.com/momar It has pics of my 3.45 rear, pbr brakes, car, motor, hooker lt headers and soforth. The pictures are really crappy, but if you look especially in some of the bottom ones you can kind of see what a mess the garages is. It is agains the wall on the oposite side of the gargage as my car and there is 3 sets of seats, a set of doors, a hood, 2 motors, and a couple sets of interior panels in the way of getting to it. When it ever comes out in the open I will get the axle code but until then you will have to suffer in your own disbelief.

Ben

 

he is not "dodging" or lieing. he does indeed have a bw 3.08 non posi drum sitting in his garage, how do i know this, we have been freinds ever since 5th grade, in fact i use one if his comps to post with right now, and he has one (1) 85 ta, almost everything but body from anouther 86 TA (2), a hole interior form anouther 89 GTA, (3), that makes one (1) compleat car, and most of the parts from two (2) other ta's. this equall a lot of crap in the two (2) car garage. who can say that they have almost 3 cars worth of cars in there garage. not many. he or I will get pics as soon as we clean outh the stuff. by the way a lot of the stuff is for sell. let him know if anyone is interested.

thank
anthony

watch out mark sheilds, ben is a post ***** too, he is comin after ya

 

This board is just full of 'em.
I have NO DISBELIEF! NO DISBELIEF! NO DISBELIEF!
LISTEN!!
If someone was to forge the axle code, which are you going to use? You obviously have to use the right one.
That is all I have been concerned with.

 

I have AT LEAST that much Camaro stuff in my garage ----- & It's only a ONE CAR garage !!!

My interior stuff and electronics are in the house, and the body parts are in my shed because of an obvious lack of space in my little garage !!!







I believe that the rear is what you say it is ---- what use is there in forging the codes ????? What gain is to be had by doing that !!! My reason for remaining interested in this thread is,........ WHY does such a rear end exist in the first place !!!

I am still thinking that it's an imported car or something.....

 

Guys, I DON'T CARE if it is a B-W 3.08 or not, posi or not, but in my Haynes 1982-1992 Firebird Repair Manual, there is a rear-end code listing for the 1985 B-W 3.08 (standard)---10032243.

For the B-W 3.08 posi---10032244 and 10032268.

The 3.27 standard---10032245.

3.27 posi---10032246

I personally don't take this info for gospel but IT IS listed under the B-W 1985 rear ratio section.

However, there are some questions on some of their other numbers listed there. Such as 3.42, 3.75 (yes-3.75). AND I see some other inconsistancies in other parts of the book.

JUST a FYI.

jms

 

RPO-ly speaking,

BW 9bolts only, axle codes are the following:
(these are borg warner codes from a 1986 GM manual (helm), so some/all/none may have been installed in GM cars, but they were spec'd as part of the assembly line)

RPO=GU4 (3.08 ratio) for all following:

Axle code = 8XB - drum brake, non L/S
Axle Code = 8X0 - drum brake, L/S
Axle Code = 8XU - disc brakes, L/S
No option for non L/S with disc brakes.

And for the picture above with drum brakes and 3.45 gears, I can't find a code for a non-L/S diff, but I can fine one with drums:

RPO = GM3 (3.45 ratio)

Axle code - 8XW - disc brake (optional could have had drums), L/S
Axle Code - 8XQ - disc brakes, L/S

In 1989, I can only find 3.27 and 3.45 in the BW section. It stands to reason that GM made things simplier with less options. I recall my 1989 formula was only available in 4 colors with the optional 2 tone.



I will check the axle I have from the 1988 TA and see what's stamped on it. I have a feeling it was a 3.08 ... could not see why someone would swap 3.70's in a car that had 3.45's. 3.08's sure ... but not 3.45s. Seems like a big cost, but then again I am cheap.

Mark.

 

Actually the rear with the drum brakes is a 3.08. It is my other 9 bolt that is a 3.45. It was out of an 87(the 3.45) and I converted it to pbr brakes.

 

As far as being imported, my car was built in van nuys (sp?). Where is that at? I have looked at the carfax report, and it has been in the states all along.

Ben

 

Even when I bought my 1989, it was made in Van nuys. I live in Canada. So there really isn't any difference between canadian and US cars other than the gauges and documentation.

Mark.

 

Yes, but the carfax report also showed it as being in the united states its whole life. Also, the origional owner was from Il I believe. I could find out for sure after while.

Ben

 

Ok, here we go it was purchased on June 20, 1985 in Decatur Il by Bruce E. Walkup with 53 miles on it. Dont think it was imported huh.

Ben